A brilliant and addictive minimalist puzzle game! Highly recommended.

I think Keksfuchs has a point about it lacking a campaign mode, although that doesn't bother me at all. I would imagine a campaign mode would use a similar branching tree system where levels are selected based on the player's location in the tree, but having two screens with branching trees (one for campaign navigation, the other for the levels in the campaign) might get confusing.