- Released: 1991-
- Developer: Hewson Consultants | Bits Studios
- Genre: Platform
- Mode(s): Single Player
*Nebulus is a video game created by John M. Phillips and published by Hewson Consultants in the late 1980s for various home computer systems. International releases and ports were known by various other names, including Castelian, Kyorochan Land (キョロちゃんランド, Kyorochan Rando), Subline and Tower Toppler.
The Game Boy and Nintendo Entertainment System versions of Castelian were developed by Bits Studios and released in the United States by Triffix and in Japan by Hiro Entertainment; in these, the lead character is called Julius. The Game Boy and Nintendo versions were later released in Japan as Kyoro Chan Land, which replaced Julius with Kyorochan, jewels with Chocoballs, altered the enemy graphics and (in the Famicom version) added a password system and a pause feature. The Italian bootleg version was called Subline. The Nintendo versions were composed by David Whittaker, and the title songs were covered by Whittaker from the original Tower Toppler game's title screen. In the Famicom version, the title screen plays what is the bonus game theme from the US version.