Nebulus (also known as Tower Toppler or Castelian on the NES) is a Platform Game developed by John M. Phillips for the Commodore 64 and ZX Spectrum and originally released in 1987 by Hewson Consultants Ltd. It was ported to many other computers; it was also ported to the Nintendo Entertainment System and Game Boy as Castelian by Bits Studios. A sequel, Nebulus II: Pogo a Go Go!, was developed by Infernal Byte Studios and released for the Amiga in 1991.
On the planet Nebulus, eight treacherous towers have arisen from the seas. As a big-eyed green hopping creature named Pogo, your mission is to climb each tower by scaling the ledges that circle its exterior. The towers are viewed in a rotating perspective; all of them feature lifts are needed to reach higher levels, and tunnels which connect opposite faces and are useful for avoiding enemies. You can also shoot bouncing balls and flashing blocks out of your way with snowballs. Once you climb to the top of a tower, it will crumble into the ocean.
Tropes appearing in this game:
- Bonus Stage: Between towers, "catch some fish for bonuses" Under the Sea. In the NES version, these underwater bonus stages were replaced by side scrolling platforming levels.
- Bubble Gun: The submarine in the bonus stages shoots air bubbles at fish.
- Every 10,000 Points: Extra life every 5000 points.
- Faceless Eye: Some of the enemies are disembodied eyeballs. They are invulnerable.
- Fake Platform: Some ledges look normal until they dissolve when you stand on them.
- It's All Upstairs from Here: The game is all about climbing towers. Some of the ledges form stairways, but the lifts are often more important.
- Knockback: Getting hit by enemies will make you fall to a lower platform, or into the ocean (which is fatal). It can be used to reach otherwise inaccessible platforms.
- Timed Mission: You need to get to the top before the timer runs out.
- A Winner Is You: Completing the game produces a message that says little more than "Congratulations".