Atari ST MIDI musicThe Atari ST version has a special trick. The developers programmed the MIDI interface to play the game music. If you hook a MIDI synthesizer to the ST, the game music will play over your MIDI device.
Commodore 16 versionThe C16 port is even shorter than the C64 version, as it features only the two first levels, with simplified gameplay (one weapon, less enemy types). There's no music and no title screen picture.
Spectrum versionThe Spectrum version does not load on Spanish +2A or +3 models, as their ROM mapping is slightly different from the UK models. An unofficial patch is available however.
Contributed by Scott Monster (919) on Jan 19, 2005. [revised by : Patrick Bregger (98690), Rola (6424) and Martin Smith (63217)]. -- edit trivia