Really, really original and well executed as well. I absolutely love procedural games because of the replay value and your game is an absolute joy to play over and over again. Well polished, distinct style, creative gameplay.
As mentioned below, the music choice is also interesting and a big plus because of that. But it's loud indeed, it sounds distorted even (at low volume, so not my speakers ;-) ). Would definitely tune that.
Only one small improvement I could think of. Some sort of level indicator of the enemies. I now got killed by some tough enemy that took too many hits to kill before it reached me.