Dont know what to say
the general idea is great, the graphics are a little plain, maybe is the background, it may change for every level, maybe adding a map or a task, like geting to a sacred mountain, something like that.
the music could also variate, not just one track.
after a minutes i get to get pass every stage. the onslaught mode is more fun, maybe you could change the characters aspects depending in their color.
thats all.