I'm a sucker for a game with an upgrade system, so I loved it. Going from when you can barely kill one rabbit to the point where you're mowing down tens of them in seconds is so satisfying.
I think the balancing could use a bit of tweaking. I definitely did get to the point where I was killing most of them before they even came on the screen, but I definitely had a lot of fun with it. And also it could use some sound.