Rath-Tha is a vertically-scrolling shoot-'em-up. In the far future the human race built a long tube that absorbed all of the rubbish generated by the planets in the system. T'ufo - a planet notorious for its dirtiness - has sent a rat-shaped ship called Rath-Tha to destroy the tube. The game commands a ship to destroy Rath-Tha. The game consists of four phases. Starting off inside the tube, the player fights off swarms of enemies. The ship can be moved to any part of the screen while shooting. Next, there is an area with megatronic generators. In the third phase the ship leaves the tube and reaches outer space. It needs to avoid torrents of waste that are immune to shots. The chemical substance alters the ship's controls. Finally, the ship reaches Rath-Tha and needs to fight inside to destroy the core. There are bonuses such as metal waste that restores shield, trash bags to regain energy, and radioactive canisters for temporary immunity. The player also carries three CODA codes to destroy barriers inside Rath-Tha.