Todd Cope developed "A side-scrolling platformer with 3 episodes, structured similarly to the Commander Keen games."
This game was an original platform action adventure game inspired by games such as Commander Keen, Jazz Jackrabbit, and Super Mario Bros. The game was divided up into episodes, much like Commander Keen, with each episode introducing new areas to explore and new character abilities.
The game would feature a world map which was side-scrolling like the rest of the game with doors that would take you to various levels. You would progress through the game by getting through the levels and finding certain items that would allow you to progress further on the world map.
There were also horizontal shooter levels that featured gameplay similar to R-Type.
— Todd Cope, T3 History, t3-i.com
Fat Boy was a side-scrolling platformer in the vein of Super Mario Bros. and Commander Keen. The game took advantage of Game-Maker's level link system to implement an overworld map which was just another side-scrolling level with doors that led the various levels. The game had an intro cartoon that depicted Fat Boy standing there while a dump truck full of food backed up toward him and proceeded to dump the food into his mouth.
The gameplay in the first episode was all about enemy avoidance. I can't remember all that much about the levels except for a few that stood out to me. One had Fat Boy in a space ship that was flying through space. I implemented a parallax scrolling starfield by drawing a tile animation that looped seamlessly. The effect looked great and gave the level graphics some much-needed depth. This same level had conveyor belts that I implemented by having a gravity tile just above an animated conveyor belt tile.
There was one level that was a side-scrolling shooter that had Fat Boy riding in some kind of vehicle shooting enemies. This level used the gravity trick to enforce the scrolling.
Another level had Fat Boy making his way through an ancient temple. I used this level to experiment with lighting effects and 3D graphics drawn by hand. This was the best looking level of the bunch.
The second episode added an attack. Fat Boy could shoot a green projectile from his mouth.
— Todd Cope, unknown source