Quarth might be best described as a mix of a shooter and Tetris. You control a ship that moves horizontally at the bottom, and shoot incoming blocks or groups of blocks (adding tiles to them) to give them a rectangular shape and make them disappear. Each level scrolls at an increasing speed until you reach the end, and you lose if a block reaches the line floating above the ship.
This is a tool-assisted speedrun, made on an emulator, using frame-by-frame shooting, savestates, and rerecords to overcome reaction time and human error. As such, it is purely a form of entertainment, and is not designed to show skill.