Gimbal Mahjong

In the old teahouses the mahjong trays sat in brass gimbals so a waiter could carry a game across the room without spilling a tile. Here the gimbal turns on purpose: tip the tray a quarter and every tile slides toward the new floor, and twins that land side by side clear on their own.

Mahjong connect where the tray turns: join twin tiles with a line of two bends at most, turn the board and watch tiles slide and land in pairs.

Tap a tile, then its twin. They clear when a line with at most two bends (three straight runs) joins them through empty cells, over cut-outs in the tray or round the outside of the tray. A twin with no such line is a miss: the line shows in red where it is blocked. Gravity is always on: when a pair clears, the tiles above it slide down. Press Turn left or Turn right to turn the tray a quarter: the tiles stay upright and slide toward the new floor. A tile that comes to rest touching its twin clears with it on its own, a landing pair, and each wave of landings can set off the next. Most boards start with three turns (the first board two, hard mode one fewer); each landing pair and every fifth join in a row without a miss marks the turn meter, and three marks give a turn back. Joins in a row also raise a multiplier up to x5, and a miss resets it. If no pair can be joined and no turn is left, the tiles shuffle and the clock loses 10 seconds. Clear the tray before the clock runs out. On a keyboard, the arrow keys move a cursor over the tiles, Space or Enter picks one, Q and E turn the tray, H asks for a hint and B opens the boards.