Sand Blocks

Block-dropping where the blocks do not stay blocks. Place one on the grid and it collapses instantly into colored grains that pour down and settle into whatever shape the pile beneath them allows, so the tidy rectangle you aimed for becomes a slope the moment it lands. A line clears only when a full horizontal run is all the same color, which means planning around a material that refuses to hold still. Three shapes at a time, any order, and the game ends when the sand reaches the top.