Tetris. You stack the bricks, the lines disappear, and the troika drones on in the background. 99 Bricks is a bit different, in that as the tetrominoes fall and stack, they don't disappear when lines form. This time, your goal is to make the tallest tower that you can. A higher tower means a higher spot on the leader board.
Just be warned though, your tower is not steady.
In a twist on the classic block stacking game, 99 Bricks challenges you to make a brick tower using standard Tetris play mechanics. [Left] and [right] arrows move the falling brick back and forth, [up] rotates the block, and [down] drops it. You're also given [Z] to zoom out and see the whole tower, and [C], which can throw out the current brick if you don't want to use it. What makes this game unique is that the playing field is not based on a rigid grid, like what you're probably used to. Improperly placed blocks can tip and tilt, just like a real (two-dimensional) block tower. You've got to plan ahead and make sure your bricks are structurally sound, more than just fitting into holes.
As soon as a falling brick touches your tower (regardless of which side), it's out of your control, even if it means your brick falls past another ten bricks straight down. It's possible to "nudge" a set of bricks with proper placement and timing from your current brick, but whether or not this is a good strategy is up to you.