Hatetris

Closest in name to Hatris, this falling-block puzzle is however closest in spirit to Bastard Tetris, the cruel and sadistic Tetris variant that analyses the playfield and withholds the shapes of piece the player would find useful given current conditions, preventing all but the cleverest and most patient players from ever filling every space on a horizontal line with block segments and completing a line, let alone five at once.

This variant is unusual in that it fails to elapse in real-time: the player has as much time as they like to maneuver their block into place using the keyboard arrows. Gutsily, the nasty computer AI supposes that the time advantage won't be much to the human player's advantage; says the author, "No, there is no gravity: on the one hand I simply never got around to implementing it and on the other hand I honestly think that gravity is the least of your problems with this particular Tetris clone."