Incidentally, I never seen anything from the Playstation version, do the graphics look just like the Mac or Amiga versions, or does it look a little different?
It's high-res, unlike the amiga version etc, because it's on a TV screen. But the graphics are noticeably different from the mac version as well, presumably from being done by different people.
Also, the problem you described about the mac version in that you can't quite tell if the lemmings have gone off the edge of something (which, incidentally, I've never noticed) is much much worse on the playstation.
It probably is based off the win95 version--that seems very likely.
Other differences (to the mac version usually, since I don't know enough about the others):
It's missing 6 levels of Lemmings (the four special graphics levels, All the 6's and the Fun incarnation of We all fall down) and 5 of ONML (Tame 17-20 and Superlemming, to my dismay),
Many levels are missing water that goes along the bottom of the screen, which usually just serves a decorative purpose, but it makes the levels look a lot plainer. Call in the bomb squad is even missing the decorative water along the top,
Triple Trouble has 12 builders and Steel mines of Kessel has 20 of everything, much to my dismay again since these were always the hardest to pass, especially the latter, on the mac. otoh, this made them possible to be passed, so it's not all bad.
Also, Come on over to my place: save 40/50, not 100% (yes I am aware that this is the case on the PC),
and The Crossroads: save 70/80, not 100% (although here I actually passed it with 100% anyway so nyah).
And Save Me only required one attempt at the final section (after, to be fair, about 20 or 30 for the first part); it seems to be more lenient here.
Plus, the lemmings walk off the top of the screen, which seriously affects Going Up........, where I had to use an elaborate system of blockers and bombers and stuff, and to a lesser extent Mind the Step, which only needed an extra builder.
But anyway, all that is hardly even worth mentioning when you realise the biggest bad part, namely the builders; their mechanics seems to be completely different, with the net effect that bashing from a bridge is impossible unless the builder is shrugging. This used to keep me from solving Lemming Hotel (Wild 2), although the other day I also used a digger so that the returning builder would stop and solved it in one try, ironically. Building from the very edge is also nigh-on impossible for the high-res reasons that I mentioned before, and that here the builder's feet start in the middle of the first step, not the very edge as I'm used to. This makes Livin' on the edge quite difficult, although iirc the mac only has 6 builders yet the playstation has 10.