Hard and tricky.
Great Permutator is a puzzle. If you are into clever engineering puzzles like LightBot, Manufactoria and SpaceChem, this game is for you.
Features
50 levels (+15 bonus levels)
10+ types of action blocks
16 not-so-easy achievements
Global score leaderboard
Nice pixel art graphics and cool soundtrack
Level editor with sharing levels via Internet
One in which you will have to build a complex system of conveyors and various devices so that the colored boxes can travel across the factory and arrive at right places and in right order. Great Permutator.