Block Blast

Block Blast hands you a grid and a small tray of block shapes, then leaves the rest entirely up to spatial planning: place each piece to complete full rows or columns, and they clear, Tetris-style, except there's no falling timer forcing your hand.

That lack of a clock is deceptive, because the real pressure comes from the tray itself: you're given a fixed set of shapes to place before the next batch appears, and an awkward piece placed carelessly early on can leave gaps too small for anything in the next batch to fill. Clearing multiple lines with a single well-placed piece is worth planning several moves ahead for, since the score bonus scales sharply with simultaneous clears rather than rewarding one line at a time. Cubes 2048.io scratches a similar grid-planning itch if merging numbered blocks appeals to you more than clearing lines.