Puzzle Express is an interesting fast-paced Flash game, cross between Tetris and... something else. You're presented with a box—a boxcar, hence the "Express"—and your goal is to fill it with Tetris-like pieces that appear on a conveyor belt. The catch is, you have to fill it up completely—no gaps—and within a time limit. Sometimes you're presented with two boxcars side-by-side and must fill them simultaneously with pieces from the same conveyor belt. And if your conveyor belt fills up, it's game over. When you finish filling one box, it's whisked away and another one rolls up. The game starts out easy, with just a few boxes per level, but of course that changes as you progress. Two hints: One, there's a little red square in the lower left. That's a single (1x1) piece that you can use to fill pesky holes, but you have a limited supply. And two, save 1x2 pieces as long as you can—you'll need them at the end.