I know DOS and Mac does, and maybe Windows. Amiga, SNES and Genesis does not. Don't remember the rest, although I'd guess that most don't support RR changes while paused.
The PSP lets you change the RR and skills while paused.
PSP
-scenic background on every level
-graphics very different. Much higher resolution/better looking and more detailed. Below is a list of a more proper name for them:
pillar - egyptian
marble - roman
crystal - chemical plant? (open to suggestion)
dirt - dirt
hellfire - hellfire
-removes some levels while adding some new ones
-lemmings walk slower
-many levels have more time to compensate for ^
-new voices for lemmings and new phrases. (e.g. lemmings say something every time I skill is assigned)
1. Dirt is Earth
2. Hellfire is only called Hell.
3. Only those Sunsoft levels are missing, but I can just build them in the editor.
4. Giving more time on the majority of levels, just because the Lemmings walk slower was pointless. Almost all the levels can still be beaten under the original Amiga's level times. "Just A Minute" is too easy now because it has two minutes.
5. Actually the Lemmings don't say anything when you give them a skill. All you hear is some sort of equip sound.
These are the ones that I would add to the PSP list:
1.Builders makes longer stairs.
2.You can assign a skill to a Lemming while the game is paused. When you unpause the game, the Lemmings will have the skill.
3.Miners cover more terrains.
4.Some levels have terrains with small pixels that helps Lemmings survive falls, where they are suppose to die, making the level easier.
5.Special levels such as "A Beast of a Level", What an AWESOME Level" now uses the Dirt theme. "MENACING !!" and A Beast 2 of a Level use the Hell theme.
6.The face in "Hunt the Nessy" now has an angry expression.
7.A lot of outside terrains were removed in order for the level to fit within the side limit of the background. This is why Mayhem 30 is missing the two big terrains with the bridge between them, because the level is too long.
8. The one-way arrow in Mayhem 30 is missing and so is the terrain that was on top of the two trees.
9. Walk the web rope and What an AWESOME level doesn't have stars and those pointy things on those monsters.
10.Curved Pillars are not in this version.
11.The green terrain in Tricky 4 and Taxing 7 near the edge of the steel terrain is removed. The orange terrain is now moved to the left, so the Lemmings can land on it.
12.The gray part of the flamethrower doesn't harm you and you can go through it. This makes "Feel the heat!" easier.
13.You can beat Mayhem 7 by just using dig and bash through all the poles.
14.Mayhem 3 has the wrong RR. It starts at 50 and Mayhem 24 starts at 10.
15. The third exit in Taxing 17 is not there, because the level will be too long for the background.
16. Tightrope City has terrains below the horizontal terrain, which makes it ok to use the bomber.
17.Lemmings can walk on the ceiling.
18.Fun 25 has 100 Lemmings while Mayhem 4 has 50.
19. Trick 19 has a grass terrain on the pillar that blocks the climber from climbing the entire pillar, making it unnecessary to use floater.
20.Mayhem 21 has 20 Lemmings.
That's it for now.