You have an empty Boggle-like grid and letter tiles roll down on a conveyor belt at timed intervals. If you do not grab it in time, the letter will drop out of play. You take the tiles and place them on the grid creating words. The round ends when the slots are filled up, and the games ends when you have too many letter drops in a round.
Points are added up by scrabble style word scoring and multipliers for the longer the words. Rounds increase in complexity with faster intervals and larger board area.