The video game console versions had 3 additional levels. In the arcade version, the 5th level is an exceptionally long last level. The disparate elements of it were expanded in the console versions to form 3 additional levels.
[EU] Nintendo NES (dec.28, 1990) "Probotector [Model NES-77-EEC]
Microsoft XBOX 360 [XBLA] [EU] (nov.8, 2006)
[EU] Nintendo DS (oct.26, 2007) "Konami Arcade Classics [Model NTR-ACXP-EUR]
[AU] Nintendo DS (oct.29, 2007) "Konami Arcade Classics"
[EU] Sinclair ZX Spectrum (1987)
[EU] Commodore C64 (1987)
[EU] Amstrad CPC (1987) [64 ko version] : FX only.
[EU] Amstrad CPC (1987) [128 ko version] : FX and Music.
PC [MS-DOS] [EU] (1987)