1001 Video GamesNebulus appears in the book 1001 Video Games You Must Play Before You Die by General Editor Tony Mott.
Canceled portsJohn Romero actually did the Apple IIe port of Tower Toppler but Epyx canceled the port along with all their other game ports when they were strapped for cash because they were pouring all their money into Atari Lynx launch title development. The Apple IIe version was in 16-color double-res and used page-flipping. Romero showed it off at the 1989 AppleFest in Kansas City.
The game was also ported to the Atari XE Game System, but never released. Copies of the cartridge surfaced in the late 90s, and it turned out that the XE version ran in black and white on PAL systems, except on poor display systems, where the black and white patterns turned into colours due to cross-talk on low-bandwidth colour signals. On any NTSC system the game would run in full color, looking pretty close to the 7800 version. Since the prototype uses the Tower Toppler name it probably was intended for US release, so the developers would be expecting the game to display in color and not black and white.
GraphicsFor some reason, the title screen is in 16 colors only in the EGA version. The Tandy/PCjr version uses the 4 color CGA title screen, however all other screens (including the game itself) are in 16 colors.
Japanese versionIn Japan, where the game was released as Kyorochan Land, the green colored frog was replaced by Kyorochan, a parrot-like cartoon bird who serves as the mascot of Moringa & Co., a confectionery company.
RemakeA remake of this game has been written to work on modern hardware/OS. See the related sites section for a download link.
Information also contributed by Lev Epshteyn, John Romero, and Игги Друге.