I love the idea, but I'm not a fan of, and that may be just me, mouse driven movement. That coupled with the inability to actually aim and the enemies' projectiles being so hard to dodge meant that I couldn't clear even the 2nd lvl even though I tried a lot of times, but the best I got was around 9/14 carrots.
If it were KB to move and mouse to aim I'd probably do much better, though maybe it would have been too easy then.
Also the penalty for just touching the wall is so harsh. Maybe you could put the player on a timer and crashigh into a wall would slow them down so that they would have to balance getting hit & crashing to acutally just make it in time.
To be fair, I'm terrible with the mouse and much prefer KB/gamepad, so take my whining with a grain of salt :)