THE USUAL
Pieces fall; fill a row and it goes. A/D move, W turns clockwise, Q the other way, S drops softly, SPACE slams it down, C holds a piece for later. A ghost shows where the piece will land. Clear the field's quota of rows and the next field loads; the score carries.
THE CIRCUIT
Twenty fields, each a tiling times a shape, introducing one new thing at a time: the shapes on squares first, then the other tilings, then the combinations. Gravity creeps up a little every level. After twenty it is endless — every combination, faster, with bigger quotas.
SLOPED FIELDS
Where walls step in or out, cells resting on a ledge stay there, and when a row clears everything above settles cell by cell — a cascade can fill and clear another row on its own. On a sloped HIVE or SHARD the cells slip down whichever diagonal is open, like sand. Combos multiply.
OTHER TILINGS
On SHARD and HIVE there is no straight down: pieces fall in a zigzag and turn by sixty degrees. Left and right still move one cell. Rows are rows.