Cute and fun :)
Others have already mentioned that the lives feel kind of punishing and unnecessary, and I have to agree. In fact, you might want to go a step further: let players skip to whatever checkpoint they want, or have separate small levels instead of one level with checkpoints. That way people can just try out all there is to the game without getting stuck. (I've made that exact mistake before as well though, and I know getting the same feedback again and again can be a bit frustrating, so, sorry for that)
The controls can feel a little floaty, but I suppose that's only fitting for a guinea pig in a ball. Also, I played using the touchpad of my laptop, so I suppose that made it a bit more difficult, and especially scrolling didn't work that great. Perhaps the mouse actions could have been assigned to the keyboard as well, but that is of course personal preference.