Stuck at the first level for a little while, which brings me to think: how could one, while designing a level, be 100 percent certain of the unsolvability of the level?
Great game! Not complex, but difficult and rewarding within a limited space, and also at the same time innovative with these refreshing mechanics.
Genius idea! Is there 5 levels in total? After completing level 5, the game returns to level 3.