Tetris
Tetris in the browser, with a keyboard or by touch on a phone or tablet. Play an endless marathon that speeds up every ten lines, or a forty-line sprint against the clock. Pieces turn by the standard rules, so they kick off walls and T-spins work.
How to play
Fill a row across and it clears. Four at once is worth more than four ones, and doing two hard things in a row pays half again on the second.
On the board: drag sideways to move, drag down to sink, flick down to slam, flick up to hold, tap to turn. Or use the buttons under it — they never move. A keyboard works too: arrows, Z and X to turn, space to drop, C to hold, P to pause.
Pieces turn by the standard rules, so they kick off walls and out of tight slots instead of refusing — which is what makes a T-spin possible.
Rotation that behaves
Naive rotation makes a game that feels wrong in a way players cannot name: pieces refuse slots they obviously fit, and T-spins are impossible. This one uses the Super Rotation System, the standard modern rule set. When a turn would collide, it tries a short, fixed list of nudges and takes the first that fits.
So an upright I-piece against the left wall still turns, shoved over, and a T-piece can twist into a slot under an overhang. That twist scores as a T-spin only if the piece got there by turning and three of its four corners are packed.
Pieces come from a shuffled bag of seven, so every shape appears once before any repeats. The next five are always on show.
Marathon and Sprint
Marathon asks how long you can hold on. The level climbs every ten lines, gravity gets faster, and it never gets slower. It ends when the stack reaches the top.
Sprint asks how fast you can clear forty lines. The speed holds still, so the clock is the only pressure.
In both, a piece gets half a second on the floor before it sets. Moving or turning it restarts that timer, up to fifteen times, so you can slide a piece into place but cannot stall forever.
Scoring and records
Scoring follows the standard guideline. One, two, three and four lines pay 100, 300, 500 and 800, times the level, and a T-spin pays more than the same lines cleared the ordinary way.
A tetris or T-spin that follows another pays half again. Clearing lines on consecutive pieces builds a combo, and emptying the board completely pays a bonus of its own. Slamming a piece earns two points a row; pushing it down earns one.
Records stay in your browser: best marathon score and most lines, and your fastest finished sprint.