Did you buy Dead Island
on the PC and did you do it through Steam? Chances are, you encountered bugs and some easy ways to cheat. Well, there's a reason for that.
Looks like the development build of the game was released
on Steam rather than the retail version. Whoops. That explains why you can do things such as no clip just by pressing Y.
I guess this should be a lesson to any software company. Make sure when you do a final release to the digital distribution of your choice, the software's labeled as one that's not for public consumption.