I like this idea a lot! I have a couple of thoughts:
Stuff I liked:
- Unique concept
- Addicting gameplay loop
- Kickass metal soundtrack
Stuff that I think should be changed:
- I felt a little dizzy after playing this, maybe do something to eliminate that feeling as much
- Most of the game, for me, was spent waiting until I got to the other side to attack the enemies again. You could probably minimize this by adding more enemies and making the time to kill smaller.
This was an impressive programming and art feat for 9 days! Keep up the good work!