The Castle Greedy is the final level in both versions of the game Ristar.
The headquarters of the infamous Greedy, there are towers of an unknown origin and technologies in the surroundings, and the whole place is surrounded by flashing neon-type lights! The overwhelming towers and lights make the place look like a fortress or castle, and it is the reason this place is also referred to as the Castle of Greedy or Greedy Castle. The tyrant is so arrogant that he also refers to his stronghold as Planet Greedy!
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When Ristar defeated Uranim on Planet Automaton, Inonis escaped with his cyborg creation in a spaceship to Castle Greedy. Inonis also brought the Artificial Black Hole technology, which can suck all happy feelings in the universe and Ristar had to stop the technology from completion. After a fight with Eyebar - 555, and a battle with Greedy, Castle Greedy start to self-destruct and exploded. Ristar, Greedy, Inonis, and Uranim were the only ones to have escaped.