What Makes Nebulus Great: C64 Analysis

1 August 2020 · Updated 26 February 2026

Nebulus, released by Hewson in 1987, became a commercial hit on the Commodore 64 and various other platforms. Developed by John M. Phillips, the game demonstrated that innovative visual techniques could coexist with compelling gameplay rather than merely impressing viewers.

Notable Strengths

Control scheme — Natural, responsive character movement enhances immersion, with Pogo the frog responding immediately to input without floaty physics or input lag
Compelling gameplay loop — Engaging interactions with platforms, elevators, hidden passages, and tower progression create satisfying exploration combined with time pressure
Difficulty progression — Better-balanced challenge curve than many contemporary C64 releases, teaching mechanics gradually before demanding mastery
Visual presentation — The cylindrical tower rotation effect remains impressive decades later, creating genuine 3D perception through clever sprite and character manipulation
Sound design — Memorable aquatic, bubbling audio effects establish atmosphere without overwhelming the experience, complementing rather than dominating
Atmospheric details — Subtle touches such as deepening submarine shadows near the ocean floor demonstrate attention to polish that elevates the entire production

The submarine bonus stage featuring parallax scrolling deserves special recognition as a reward that players anticipate rather than endure, providing respite between tower challenges while maintaining engagement.

Areas for Improvement

Occasional demands for precise pixel-level jumping that can frustrate players approaching platforms from unexpected angles
Jump input requiring fire plus up combination when single-button jumping would be preferable and reduce hand strain during extended sessions
Two notable bugs: erratic wrench timing that creates unavoidable damage situations and performance slowdown on level 6 when multiple sprites overlap
Uneven difficulty curve where level 5 proves harder than subsequent stages, creating a difficulty spike that discourages progression
Absence of background music during gameplay, leaving players in relative silence beyond sound effects
No time-extending collectibles to reward exploration or provide second chances on challenging towers
Sparse enemy sprite variety compared to the environmental diversity, with similar threats appearing across different tower themes

The character animation techniques from Nebulus provided inspiration for rotation mechanics in games like Parallaxian, where smooth directional sprite changes contribute to responsive-feeling controls. Phillips’ approach to pre-rendering rotation frames informed similar techniques in subsequent projects.