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B.C. II: Grog’s Revenge

Last updated: January 23, 2026

Overview

B.C. II: Grog’s Revenge is a 1984 action game developed by Sydney Development Corp. and published by Sierra On-Line for the Commodore 64 and ColecoVision1. The game serves as the sequel to B.C.’s Quest for Tires (1983), which had won several awards for best animation, graphics, and sound2. Both games are based on Johnny Hart’s popular newspaper comic strip B.C., which first appeared in the 1950s and features prehistoric characters in humorous situations3.

The game features the character Thor, who rides a stone unicycle through a maze of mountains in search of the “Meaning of Life”4. Unlike its predecessor, which featured a more linear, Moon Patrol-style gameplay, Grog’s Revenge offers players greater freedom of movement across interconnected mountain paths5. Contemporary reviews praised the game as a “stunningly impressive programme” with “hilarious graphical touches and jolly gameplay”6, though some critics noted that collecting clams and avoiding obstacles could become monotonous3.

The game was released on multiple platforms through various international publishers, including U.S. Gold in Europe, Comptiq in Japan, and Erbe Software in Spain1. Notably, several advertised ports for the Atari 8-bit computers, ZX Spectrum, BBC Micro, and Amstrad CPC were never actually released6, making the existing versions particularly significant for preservation efforts.

Story Summary

Thor has completed his Quest for Tires in the previous adventure. Now he must discover the Meaning of Life4. But this philosophical journey won’t be easy—the Meaning of Life is hidden away somewhere in a long maze of mountains7. Thor must navigate treacherous paths on his trusty stone unicycle while avoiding the menacing Grog, who stalks him throughout his journey5.

The only way to reach Peter and the toll bridge that leads to enlightenment is through the “real scary caves”8. Each mountain is covered with clams, the currency of the prehistoric world as established in Hart’s comic strip6. Thor needs to gather 100 clams in order to pay the tolls and advance through each mountain4. Peter, a character from the original comics, serves as the toll collector who guards passage between mountain regions9.

The game culminates in a quest across multiple mountain sets, with Thor dodging obstacles and outwitting Grog to reach the ultimate prize. However, the meaning of life itself proves to be “unpleasant” according to player accounts2. When players finally reach the last mountain, a huge sign tells Thor that the Meaning of Life is to the right of him, but Grog is already waiting—forcing players into a cave to the left in search of an alternate route10.

Gameplay

Interface and Controls

B.C. II: Grog’s Revenge is controlled via joystick (Port 2 on the Commodore 64)11. The game features tight, responsive controls that give players full responsibility for their actions—“you only have yourself to thank in the event of another lost life”12. Unlike the predecessor which was essentially “on rails,” this sequel features 4-directional movement allowing Thor to explore the mountain paths more freely5.

The stone unicycle’s physics create a distinctive feel, with “the toddling unicycle, the waving head of hair, the charming grin and the funny crashes” making Thor “one of the most likeable characters of all times”3. The game supports both single-player and two-player modes, with players taking turns11.

Structure and Progression

The game structure varies significantly between platform versions. The Commodore 64 and Coleco ADAM versions feature the most content with 15 stages organized into three sets of 5 mountains each6. The MSX and ColecoVision versions contain only 5 stages total6.

Players can choose from three mountains of increasing difficulty at the start10. Each mountain features:

  • Outdoor paths: Winding roads around mountainsides where Thor collects clams
  • Cave sections: Dark interiors where Thor’s unicycle inexplicably features headlights5
  • Toll bridges: Checkpoints guarded by Peter requiring 100 clams for passage4
  • Warp tunnels: Hidden shortcuts with number codes in each mountain level3

The level progression follows a lettered system (A through F), with warp tunnel codes documented by players:

  • Level A: Code 22 (to Level B)
  • Level B: Code 23 (to Level C)
  • Level C: Code 44 (to Level D)
  • Level D: Code 45 (to Level E)
  • Level E: Code 62 (to Level F)13

Puzzles and Mechanics

The core gameplay loop involves collecting clams while avoiding hazards and the pursuing Grog3. “Collecting clams is okay. But what raises the game a couple of notches is how you have to develop a strategy to avoid Grog!“3. Players must balance efficient clam collection with safe navigation around obstacles.

The game lacks continues and has no pause feature, creating significant challenge10. Death comes through various means including hitting walls, falling off edges, and encounters with Grog. Notably, “the strength and appeal of Grog’s Revenge is also its weakness, because it’s much more fun getting killed off than collecting clams and freewheeling round the mountain”14—the cartoon death animations proving particularly entertaining to players15.

Reception

Contemporary Reviews

The game received generally positive reviews from the gaming press of the mid-1980s, with particular praise for its graphics and animation.

Zzap!64 awarded the game 91% in their June 1985 review, calling it a “stunningly impressive programme”6. However, this score was later corrected to 75%3. The review was conducted by Gary Penn, Julian Rignall, and Bob Wade11.

Computer and Video Games gave the Commodore 64 version 87% in 1989, praising its “hilarious graphical touches and jolly gameplay” and describing it as “both addictive and highly amusing”6.

Commodore User provided multiple scores: 4/5 in June 1985 from reviewer Mike Pattenden, and a later 8/10 in June 198811. The original review stated: “The joy about this game is the graphics which are marvellous. It’s like being in a cartoon, because the whole thing is superbly animated”14. The review concluded that “that would have made it a classic instead of just plain great”14.

Commodore Format gave the game 70% in March 1994, calling it “definitely a game of the old school” and “a fun little diversion”6.

Additional reviews included:

  • Commodore Horizons: 6/10 (June 1985)11
  • Home Computing Weekly: 3/5 (May 1985)11
  • Your 64: 2/5 (July 1985)11
  • C&VG: 6/10 (July 1985)11

Compute! Gazette also published a review in their September 1985 issue (Issue 27)16.

Modern Assessment

Modern retrospectives have maintained generally favorable opinions of the game, with community sites celebrating its charming presentation while acknowledging gameplay limitations.

Aggregate Scores:

  • MobyGames Critics: 70% average (8 reviews)2
  • MobyGames Players: 3.6/5 (25 ratings)2
  • Lemon64: 7.7/10 (85 votes)3
  • C64-Wiki: 7.26/10 (27 votes)3
  • C64games.de: 9/103
  • Kultboy.com: 6.67/10 (3 votes)3
  • My Abandonware: 4.9/5 (10 votes)15

Community members continue to appreciate the game’s qualities: “A real classic. Very good collect’em-up-game with funny cartoon grapics. Great fun”3. Another player noted: “BC II - Grog’s Revenge is an easy game to pick up and play”12, while acknowledging that modern standards may find it lacking compared to contemporary expectations10.

Development

Origins

B.C. II: Grog’s Revenge emerged as a direct sequel to the successful B.C.’s Quest for Tires, released in 19832. The original game’s critical and commercial success—including awards for best animation, graphics, and sound2—prompted development of a follow-up that would expand upon the original’s formula while maintaining its connection to Johnny Hart’s beloved comic strip3.

The development was handled by Sydney Development Corp., a Canadian studio that had established expertise in creating licensed games with strong cartoon aesthetics1. The team opted to move away from the Moon Patrol-style side-scrolling of the original, instead creating a more open exploration-based experience that gave players greater agency in how they navigated the prehistoric landscape10.

Production

Development was led by designers Rick Banks and Michael Bates6. The game maintained the comic aesthetic of its predecessor but employed “more restrained colors” in its visual presentation, primarily featuring grey and blue tones rather than the brighter palette of the first game3.

The programming team included J. Stuart Easterbrook, P.C. Kelly, and Tris Orendorff as coders, while J. Meinert and Scott Fiander handled the graphics11. The result preserved the cartoon-like quality that made the original notable while adapting it to the new gameplay structure.

Development Credits:11

  • Designers: Rick Banks, Michael Bates
  • Programmers: J. Stuart Easterbrook, P.C. Kelly, Tris Orendorff
  • Graphics: J. Meinert, Scott Fiander
  • Composer: Paul Butler

Cancelled ZX Spectrum Version

A ZX Spectrum port was in development at U.S. Gold, being worked on by programmer Dougie Burns17. The version was reportedly progressing well before being cancelled. As Burns later reflected: “I’ll always regret not finishing Grog’s Revenge for US Gold, because it was looking good”2. The game was advertised in UK magazines during 1985 with a planned price of £7.9517, but Burns was ultimately reassigned to other projects before completion18.

Technical Achievements

The game’s animation system was particularly celebrated, continuing the visual excellence established in the original. The cartoon-style graphics impressed contemporary reviewers—“It’s like being in a cartoon, because the whole thing is superbly animated”14. The death animations proved especially memorable, with players recalling decades later how they enjoyed “the cartoony style of death animations (hitting the wall & falling off the edges)“15.

The MSX version was notable for being “one of the few games that is not a direct Spectrum conversion and takes good advantage of MSX1 capabilities”19.

Technical Specifications

Commodore 64 Version:11

  • Controls: Joystick (Port 2)
  • Players: 1 or 2
  • Language: English
  • Tape Loader: Novaload
  • File Size: 37 KB15

ColecoVision Version:20

  • Format: NTSC-U/C
  • Release Date: June 1, 1984
  • File Size: 17 KB15

MSX Version:15

  • File Sizes: Various releases between 20-24 KB
  • Media: ROM cartridge and cassette format13

Cut Content

The most significant cut content relates to the cancelled platform versions. Despite being advertised in gaming magazines, ports for the following systems were never released6:

  • Atari 8-bit computers
  • ZX Spectrum (partially developed by Doug Burns)17
  • BBC Micro
  • Amstrad CPC

Additionally, the US version of the ColecoVision release removed the staff credits screen that appeared in the Canadian version. “The US version replaced the blue title screen with a more eye-pleasing style. Unfortunately, it also removed the screen that listed the game’s staff”21. An additional 1K of data was changed between the two regional versions21.

Version History

VersionDatePlatformPublisherNotes
1.01984Commodore 64Sierra On-LineInitial US release2
1.01984ColecoVisionColecoUS release with bug21
1.01984ColecoVisionColeco CanadaCanadian release, bug-free6
1.01984Coleco AdamColecoFull 15-stage version2
UK1984Commodore 64U.S. GoldEuropean distribution11
1.01985MSXSierra On-Line/ComptiqContains game-breaking bug22
1.01985ColecoVisionVariousVarious regional releases2
Budget1988Commodore 64The Power HouseRe-release11
Patched2019MSXFélix EspinaCommunity bug fix6

Technical Issues

The game is infamous for containing critical bugs that prevented completion on certain platforms.

MSX Version Bug: All MSX releases contain a programming error that makes the game impossible to complete6. “There’s a spot in the final level (Level F) where the road corner doesn’t take you to the spot where it should, but instead takes you back to the very beginning of the level, therefore making it impossible to make any more progress/beat the game”22. The bug was documented by Generation MSX: “The MSX version has a bug which makes it impossible to finish level F”23.

Technical analysis revealed the bug was caused by incorrect byte values in the phase connection lists. The Phase F connection list contained byte value 00h instead of 04h, causing an inaccessible area needed to progress. Additionally, Phase B contained a bug (04h instead of 14h) causing delayed cave exits and VRAM corruption19.

ColecoVision Version Bug: The ColecoVision version suffered from the same issue, “although it was fixed for the Coleco Canada release”6. The Canadian version remains the only bug-free ColecoVision release.

Community Fix: After 34 years, Spanish programmer Félix Espina finally fixed the MSX version in 20196. As celebrated by The MSX Channel: “34 years later, the MSX version of the game is finally fixed”13. The patch corrected the connection list errors, finally allowing MSX players to complete the game19.

Other Issues:

  • The Commodore 64 version occasionally had loading issues with certain tape loaders3
  • Controls can be “finicky with wall/fall detection” according to some players12
  • “There are not enough lives for the length of the game. Its easy to die, there are no continues, and there is no pause feature”10

Easter Eggs and Trivia

  • Warp Tunnel Codes: Each mountain level contains hidden warp tunnels with specific number codes that allow players to skip ahead3
  • Comptiq Easter Egg: The MSX version contains a hidden easter egg message in the “Comptiq presents” screen when pressing F and H keys simultaneously13
  • Headlight Anachronism: “It always bugged me how the caveman had headlights on his unicycle, I mean really?”5—players have long questioned the technological inconsistency of a prehistoric character having electric lighting
  • Comic Strip Currency: The use of clams as currency is directly lifted from the B.C. comic strip, where clams served as the prehistoric economy’s standard monetary unit6
  • Regional Title Variations: The game is also known as “BC2” and “Grog’s Revenge” in various markets, and as “グロッグス・リベンジ” in Japan15

Legacy

Sales and Commercial Impact

While specific sales figures are not available, the game achieved sufficient commercial success to warrant releases across multiple platforms and through numerous international publishers1. The game’s budget re-release through The Power House in 1988 suggests continued market interest years after the original launch11.

The predecessor B.C.’s Quest for Tires had won multiple awards, establishing market expectations for the sequel2. However, the sequel did not achieve the same level of critical acclaim, with some reviewers noting the gameplay’s relative simplicity compared to its visual achievements10.

Collections

The game was distributed through various publishers and budget lines:

  • Original Sierra On-Line release (1984)1
  • U.S. Gold European distribution (1984-1985)11
  • The Power House budget re-release (1988)11
  • Comptiq Japanese release (1985)2
  • Erbe Software Spanish release2

Fan Projects

The most significant fan contribution came from Félix Espina, who in 2019 created a patch fixing the 34-year-old bug in the MSX version6. This community effort finally allowed MSX players to complete the game as originally intended19.

The game remains available through various abandonware sites and emulation platforms, with ClassicReload.com offering browser-based Commodore 64 emulation4.

Critical Perspective

B.C. II: Grog’s Revenge represents an interesting case study in licensed game development during the early home computer era. The game successfully translated the visual charm of Johnny Hart’s comic strip into interactive form, earning praise for its animation quality that would influence expectations for licensed properties14. However, “great graphics does not always equal a great game”10, and the sequel ultimately couldn’t match the fresh impact of its predecessor.

The game’s legacy is perhaps most notable for what it reveals about software quality assurance in the 1980s. The existence of game-breaking bugs that went unpatched for 34 years—across multiple platform releases—illustrates the challenges of early software distribution and the importance of modern preservation and restoration efforts22. The community’s eventual fix through Félix Espina demonstrates how dedicated retro gaming communities can complete work that commercial interests abandoned decades earlier19.

From a design perspective, “In comparison to its forerunner Grog’s Revenge distinguishes itself in my opinion by its monotony of the course of the game. You do not have to do more than collecting clams and avoiding obstacles”3. This assessment reflects a common trajectory for sequels attempting to expand upon simpler predecessors—sometimes additional complexity doesn’t translate to additional engagement.

Downloads

Download / Preservation

MSX Patched Version

Series Continuity

B.C. II: Grog’s Revenge is the second and final game in the B.C. video game series based on Johnny Hart’s newspaper comic strip3. While the first game featured the main character B.C. in a side-scrolling chase to rescue his love interest Cute Chick, this sequel shifts focus to Thor’s philosophical quest for the Meaning of Life4. Both games share the distinctive cartoon aesthetic and stone unicycle mechanics that defined the series5.

The character of Grog, who serves as the primary antagonist in this sequel, comes directly from the comic strip, as does Peter the toll collector9. The use of clams as currency maintains continuity with the comic’s established prehistoric economy6.

References

Footnotes

  1. DBpedia – B.C. II: Grog’s Revenge – publishers, developers, platforms, Canadian development origin ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7

  2. MobyGames – B.C. II: Grog’s Revenge – release dates, credits, ratings, awards for predecessor, Dougie Burns quote ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11 ↩12 ↩13 ↩14

  3. C64-Wiki – B.C. II: Grog’s Revenge – ratings, color scheme, warp tunnels, community quotes, comic origins ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11 ↩12 ↩13 ↩14 ↩15 ↩16 ↩17 ↩18

  4. ClassicReload – B.C. II: Grog’s Revenge – story summary, clam collection mechanics, platforms ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  5. Steemit – C64 Game Memories – gameplay comparison with predecessor, headlight observation, ending description ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  6. Wikipedia – B.C. II: Grog’s Revenge – ratings, bugs, cancelled ports, Félix Espina fix, designers ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11 ↩12 ↩13 ↩14 ↩15 ↩16 ↩17 ↩18 ↩19

  7. LaunchBox Games Database – story overview, Coleco Adam platform ↩

  8. [Consolidated Research Data] – “real scary caves” quote from game overview ↩

  9. Kotaku Games Database – story description, clam mechanics ↩ ↩2

  10. MobyGames User Reviews – gameplay critique, difficulty assessment, ending description ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8

  11. Lemon64 – B.C. II: Grog’s Revenge – magazine reviews, technical specs, development credits, version history ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11 ↩12 ↩13 ↩14 ↩15 ↩16

  12. Lemon64 User Review – control assessment, accessibility comments ↩ ↩2 ↩3

  13. Ghost Archive – MSX Longplay – level codes, easter egg, bug documentation, publishers ↩ ↩2 ↩3 ↩4

  14. Every Game Going – Commodore User Review – June 1985 review quotes, animation praise ↩ ↩2 ↩3 ↩4 ↩5

  15. My Abandonware – file sizes, user ratings, regional releases, death animation quote ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7

  16. Internet Archive – Compute! Gazette September 1985 – review mention in table of contents ↩

  17. Spectrum Computing – cancelled ZX Spectrum version, Doug Burns credit, advertised price ↩ ↩2 ↩3

  18. World of Spectrum – unreleased status, Doug Burns involvement ↩

  19. MSX FX Blog – technical bug analysis, patch details, MSX1 capabilities quote ↩ ↩2 ↩3 ↩4 ↩5

  20. eStarland – ColecoVision release date, NTSC format ↩

  21. The Cutting Room Floor – regional differences, removed credits screen ↩ ↩2 ↩3

  22. MSX.org Forum – bug reproduction details, community discussion ↩ ↩2 ↩3

  23. Generation MSX – Level F bug documentation ↩

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