Hints
Build up the rewinder upgrade first. It will allow you to collect more coins at the end of each level to buy the other upgrades with.
Study where the colors are on the fixed puzzles (control parts) as the level starts, and try to shoot as many asyou can when you get a window of opportunity, while moving waves aren't in your way.
Do prioritize the fixed puzzle/control parts over the moving waves unless the waves are nearing the exit.
Glance at the receding bar at the bottom of the screen. It lets you know when the next wave will come.
Tips and Tricks
Don't rush. Buy the Rewinder, and upgrade it always as soon, as possible. With its help - and with good reflexes, of course - you can destroy the
waves before they reach the end ball, and at the end of the stage you can collect more parts, then normally, because the end ball will be much closer to the start point. With a little practise, you can collect 100 parts/level easily. Just don't be too selfish, because it's easy to ruin the whole thing with bad aiming.
