is a platform game created by John M. Phillips and published by Hewson Consultants in the late 1980s for home computer systems. International releases and ports were known by various other names: Castelian, Kyorochan Land, Kyorochan Rando), Subline, and Tower Toppler.
The game's original 8-bit release received some critical acclaim, in particular the Commodore 64 release, which garnered a Gold Medal award from UK magazine Zzap!64.
Nebulus was followed by the lesser-known Nebulus 2 for the Amiga in the 1990sGameplay
Nebulus is a platform game. The player character, a green creature called Pogo, is on a mission to destroy eight towers that have been built in the sea by planting bombs at the towers' peaks.
The actual gameplay happens at each tower in turn. Pogo starts from the bottom and finds the way to the top. The towers are cylinder-shaped and have ledges on their outside, either horizontal, forming stairs or connected by elevators. The most notable feature of the game is that when Pogo walks left or right the tower behind him turns clockwise or counterclockwise with a convincing sense of depth. This was noted favorably in reviews of the game.
During the ascent, Pogo encounters many different enemies, mostly shaped like basic geometric shapes. Pogo can shoot some of the enemies, while some are impervious to shooting. Contact with an enemy knocks Pogo down to the ledge below. If there is no ledge below, Pogo falls into the sea and drowns.
At the top of the tower, Pogo enters a door to trigger the tower's destruction mechanism. Pogo then boards his submarine and enters a bonus stage (in some versions, but not for example in the ZX Spectrum version), where he can shoot various kinds of fish to score bonus points.