Puzznic

The player has to manage gem blocks which fall to the bottom of the screen when unsupported. Gems disappear when one or more gems of the same color are touching them; however, if a single gem of a specific color is left behind, the puzzle becomes impossible to complete. The same is true when two or more gems cannot reach each other due to obstructions.

In this sense, the game is deeply strategic in the same manner as a game like Sokoban where the player always needs to consider their next few moves.