Kurushi on the PSX. A puzzle game where you had to mark squares then detonate them when a block rolled over it. The idea was to clear all the blocks before the fell off the edge of the platform or before you got crushed. Every block missed caused a row of the platform to fall away and every detonated black block also caused a row to fall. Hard as hell in the final stage, especially since the game wouldn't let you continue on the Final stage; you had to repeat the 8th.