The main thing about this game is that you can invent things with wheels, propellers and springs. The problem is that once you've designed a two-wheeled bike with an umbrella, spring and rotablades all round, in some sort of trash-pile mess, you realise that there's very little imagination needed. Glue all parts to the engine and it works. Also, poor, generic level design will have you easily forgetting what level you are on; there's green, there's ice and there's fire. Not that any of these are particularly well done either. The designers just assumed you'd come across the levers that open the doors without giving you any indication where they should be or what they open.
The building is as irritating as the physics are twitchy. The movement off vehicle is slow and you'll often die because he fell in a certain way.
And let's not forget the 'hilarious' banter between Sack and the Doc. Which wouldn't be a problem except that the speech bubble also gets in the way sometimes.
I also had a problem when the game decided to corrupt all my saves at one point. Not something I've seen in a game for a long time. Might be a one off.
On the plus side, you can rewind time to correct any mistakes. You'll be using this a lot. Not because you will fail but because it is easier to rewind than rebuild after being hit by a projectile that came from an enemy outside the screen.
If you want to use your creative mind to solve puzzles (not that there's much puzzling here) try Crayon Physics instead.