Double Blocks

Description
Double Block is a variant on Tetris with two main modes: single player and two-player.
Single-player is level-based. After completing enough lines, the level is scored based on the number of empty rows, then the next level begins. Levels start with some pre-placed blocks to make things more difficult. Two-player mode has two players playing Tetris, competing to be the last player standing. (The two players don't interact.)
Options include showing the number of next blocks and the amount of drop slide allowed (time after placing a block where it can be slid back and forth).
The game was distributed as Shareware. The registered version also had modem play, joystick control, piece designer, demo mode, explosive blocks, upside down mode, acceleration key, team mode, timed mode, and more.


