This was a fun little game, with nice clean movement and art. I would have liked a little more feedback on when I was replacing one segment's powers with a new segment (I was confused by that), and some more options for weapons would be nice.
I agree with other posters that any audio might be nice (I can recommend the rfxgen tool for crafting some appropriate sounds for arcade style games).
I encountered a bug (no pun intended) after I died and started a second run in that the first wave of enemies never ended after the last enemy was slain.