Nebulus (also known as Tower Toppler, or Castelian on the NES and Game Boy) 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:
- Added Alliterative Appeal: Certain levels in the game have this theme in their names, including "The Realm of Robots" and "The Trap of Tricks".
- Bonus Stage: Between towers, "catch some fish for bonuses" Under the Sea for extra time on the next stage - the timer display gets confused if the player gets a bonus more than 50. In the NES and Game Boy versions, these underwater bonus stages were replaced by side-scrolling platforming levels.
- Bubble Gun: The submarine in the bonus stages shoots air bubbles at fish.
- Cartoon Creature: Pogo, a small, big-eyed green alien with a big nose that hops around on two legs and defends himself with snowballs.
- Every 10,000 Points: You receive an Extra Life for every 5000 points.
- Faceless Eye: Some of the enemies are disembodied eyeballs. They are invulnerable.
- Fake Platform: Some ledges/platforms look normal until they dissolve when you stand on them. On the first two levels of the game, they appear near the starting position.
- Game-Breaking Bug: Amstrad CPC version has an infamous bug where the game would consistently freeze upon completing the final tower making it impossible to see the ending. There are unofficial patched versions that fix this, however.
- 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; but otherwise, down is the worst direction you can go.
- Market-Based Title: The Japanese Famicom and Game Boy versions were edited to become tie-ins with Kyoro-chan, the mascot for Choco Ball snack foods.
- Super Drowning Skills: Falling into the ocean at the bottom of each stage means instant death for Pogo.
- Timed Mission: You need to get to the top of each tower before the timer runs out. The NES version counts down from 100 and adds 20 each level, while the amiga version counts down from 400 and adds 50 each stage.
- Trial-and-Error Gameplay: The fake platforms are enough to require trial-and-error, but this is also amplified by the time limit.
- A Winner Is You: Completing the game produces a message that says little more than "Congratulations".