With all the running that he does, most people would think the idea of Sonic being fat is just ridiculous. This hack however, suggests otherwise. But why all the excess gut? Instead of normal gold rings, Sonic will collect high-calorie onion rings, and eat them. Each ring that he eats makes him fatter and fatter. If he eats too much, he won't move and die of a heart attack. The only way to loosen off that weight is to run continuously until the fat is gone. The more fat Sonic has, the slower he gets and the harder it will be for him to jump, or even spin if he eats a lot. Never thought I'd say this about a Sonic the Hedgehog game, but collect one ring and you have to try not to get too many at the one time. The game also includes special monitors, that get rid of all the fat that Sonic has on him (you might even call them liposuction monitors). Tails tags along with Sonic, but does not get fat, and even if he collects rings, it will be credited to Sonic. Tails is also a useful partner if Sonic can't jump high, cause he can do that for him and take out the enemies. The game is basically Sonic the Hedgehog 2, with no changes to the music, collectibles and boss levels. The onions rings do not appear in the special stages, cause in those, its back to normal gold rings. Bear in mind also that Sonic will still gain weight in his super form. 

Overall, it is a very challenging game, with Sonic having to stay as light as possible in order to complete each level. A normal Sonic 2 game wouldn't take long to complete, but this can be very time consuming, especially if you're trying to get Sonic to lose weight in a tight area. You may run out of time on a few occasions if Sonic gets stuck, due to reduced jumping ability. But stay slim, by any means necessary, and the game shouldn't be too hard, although that in itself can be quite a challenge.