Well,

The art is good and the animation but the game was too simple, and even if you kill them while their shooting the machine gun sound still goes on.

hard

this has pretty much been repeated over and over but, its a really hard game. i cant get past the 3rd screen, where theres the air current, im trying to get the key even though I dont know why the keys are good, and its just so hard i just got frustrated and stopped playing.