Ok. When I beat the game I found something out (btw you don't have to beat the game to do it that's just when I figured it out) There are ways to get into the underworld it's cool
1. Go to the first level and put on the jump in car by pressing z cheat cheat (xxxy while holding l,r at options menu) then go to the place where there is a raised bridge that has a floating wrench in between it and go down onto dirt drive towards the water and honk the horn and you should fly through the water and land on nothing and you can drive around but there are invisible walls in some places
2.go to last level get the rc car on top of krusty burger and put on the super fast car cheat
(hold down l,r at options menu and press yyyy) then go in front of school go to left back up alot and zoom off ramp on left side of the school and you should go over fence go through hill and land on nothing.
Ps. When in underworld don't get out of car and jump you can get out of car and walk around but don't jump or you will fall forever untill you quit or change mission
Added by: super sonic exe Sep 28th 2006, ID#6781