It boils down to a simple 3d puzzle jump'n'run, where you as the player get several lives to complete a mission. If you die your body may help or hinder you in your task. E.g. jump on spikes, die, new live can now jump on the body and continue on.
I hope to get some nice ideas on how to kill the player in useful ways
On the graphic representation: I used the flat 3d view before in a Ludum Dare game and it's ideal for this kind of game. Also, it's quite easy mathematically
Also, here's a picture of a hastily pixelled bunny as the player!