This one is interesting. The game is all about finding the solution to each level, and execute that solution as quickly as possible. Most screens will only award you thee stars if you complete the screen within 2-3 seconds.

Figuring out the solution to the "puzzles" was the more fun part of the game. Executing those solutions was then fairly straightforward.

Completing all marathon modes is also fairly straightforward, with the first world probably being the most challenging one.