It's pretty fun.
It is very creative to use the mouse wheel as a form of control. It would have been nice to have some kind of in game tutorial because I didn't look at the description at first and was lost at what to do.
I will say that my favorite level was level 5. I think the levels where you can go fast are the best, though that might just be because they require the least amount of skill.
A lot of the other levels felt very tight and hard to move around in. Not to mention that the animal shapes, while cute, don't make for great levels all the time.
I think something that is all about going fast with some physics would be better. Maybe I'm just bad, but some of these levels, it was hard to go very fast in them. Maybe you could have branching paths and the point of the game is to chart out the best path to go to get the fastest time.
This could be something similar to sonic where it doesn't feel like I'm going fast because I suck, but people who are good at it fly through the level and have fun figuring out which paths to take.