I think the theme song has been "inspired" by the death metal band ORIGIN's one of the greatest song off of the album Antithesis called "The Aftermath".
Here it is: http://www.youtube.com/watch?v=eLOJ-8GjSio
Fun game by the way. Not the best but cool stuff...
Fun game while it lasted, no real reason to play it more than once. Little effort is needed to play it, and only minute strategy is required.
Master medal seems broken, fought 20 waves in survival. Game says it's unlocked, but Newgrounds itself does not.
I loved the graphics and gameplay.
I find myself strangely addicted to this game. Nice job :D
Liked the challenge, but I didn't care much for the katana... wasn't anything special