I believe the version I was playing as a kid was an NTSC game, not designed for PAL machines. NTSC games were designed to run at a frame rate of 60 Hz and PAL games at 50 HZ. The gameplay worked OK running a bit slower, but the music also ran 20% slower, which is a lot! Tim Follin's interesting sample choices coupled with this unintentional slowness gave it a weird, dreamy feeling that stuck with me for the last 30 years. It's an interesting example of accidental artistic impressions.