Nice game dudes !
I would just like to talk about some problems :
-I personally think mutate is too hard to get, and the difference between the "no mutate mode" and the first mutate mode is way tooo much. I mean, if the guy dosnt mutate, it starts to be impossible after wave 10, but when he already mutate, its really simple. After wave 15, no way to absorb bodies : it desapear to fast, and enemies are more agressive.
-I like your camera, but i think it would be better to let player see more far. Actually, I only perma-shot, hoping tuching enemies out-of-screen.
-As NuclearThrones, maybe some light-effect would be nice.
Anyway, great job !