Bloxx! is a Tetris-style roll-and-write game in which you try to fill as much of your scoring sheet as possible, while not covering the numbers with which you can score points.

If you're the first player to fill in all spaces in a colored horizontal row, then you score 4 points; if you complete this same row after someone else, you score only 2 points.

The game ends once two players can't fit either of the current polyominoes into their grid. Players score positive points for completed rows and numbers circled, then lose 1 point for each space left uncovered, whether due to them creating gaps when "dropping" the polyominoes or just not being able to fit a polyomino in the top of their grid. Whoever has the highest score wins!