WarehousePanic.io is an extremely fun IO game that takes tetris-like mechanics and implements them in multiplayer. Three gamers play on one field and try to outsmart each other and the game by putting random blocks they are given onto the grid in the most efficient manner. After a certain area is covered with blocks, it disappears giving the player some points. The goal is to score more than everyone else. Sound simple enough, but after some time the playing field becomes cramped with blocks so the amount of empty space gradually declines.
If you like puzzle games and competitive multiplayer, WarehousePanic.io is exactly what you need!