- Graphic Hacks - these are the most common kind, where you replace the regular game graphics with something different (e.g. Mr. Dig Do).
- Level Hacks - these are common for Pac-Man games; altering the maze to create a different challenge.
- Gameplay Hacks - these are common in many of the Street Fighter bootlegs; multiple fireballs, etc.
- Add a freeplay mode to Donkey Kong (good for home users)
- Rearrange the levels in any way he wished
- Add a WHOLE DIFFERENT LEVEL to the game, which he calls The Foundry
This level takes a keen skill in jumping.
- Don't even worry about the hat in the bottom right corner.
- Across the first four gaps, you need to make sure you don't hit your head on a conveyor platform above, or get burned from below.
- The conveyor platforms are the tricky part. As you can see in the pic, you need to ride on the lower-level platform to move across. As you're going across, platforms continue to come at your head from the opposite side. You need to jump up to it then immediately walk back down to your previous platform. You need to do this all while making sure you still don't get burned from below; those fireballs go all the way up to the second conveyor.
- Once you pass the second set of platforms, it's just three well-timed jumps and you're home free.