I really, really like the game. The concept and graphics are spot on, so are the sounds. However, the game fell apart for me on the last level. I think the controls are not fit for a level like that. You have to make so many precision turns, and the intertia and input lag make it very hard to do. I wasn't able to beat the last level even though I knew exactly what I had to do. It takes what was a fun little puzzle game and turns it into a frustrating trial of perfect execution.
I think if there are two routes you could take to make a great game out of this:
A) More spacious levels like the first four that have more margin of error/fewer potential errors
B) or make the controls more responsive and decrease the inertia and you can make the levels as complex as you can imagine.