snake, sonic, and lucas have been changed so far. It's a demo with only 14 characters. Obviously they have to edit them.
Snake's grenades explode almost instantly after dropping them. I'm really disappointed that they killed his camping game. He can only have one grenade out at a time as well...they improved the damage of his explosives in general but...I don't know. Apparently his game revolves around sticking c4 in between combos and grabs. At least you can still grenade -> shield punish everything still. His nair is godly imo, I mean it was so laggy in brawl and now with l-cancel it's ridiculously good.
Lucas was pretty much sped up in some aspects, no more release grab infinites, and um that's it? He was a somewhat technical character in brawl so the overall speed up as helped him in that regard.
I tried sonic a bit, but I couldn't do **** with him. Maybe because I hate him in the first place.
Btw you land on your feet not your knees in PM so the timing for things is quite a bit different especially for wavelanding. You land faster than you do in melee I think though I'm pretty sure they changed the frame rates to keep it similar.
It's easier to moonwalk. The physics are whack. I personally notice the gravity effects on attacks because I SDI everything including finishing moves that I know would kill me anyways, but man it seems like everything kills at earlier percents. You have to DI bad on purpose to maximize your trajectory. For example marth's fsmash seems to have that "invisible ceiling" effect though not as dramatic, but just an example how the physics still need work.
Oh also G&W's nair was changed (I dont like it, but it really makes him a lot more unpredictable because it's a quick killing move you don't really expect). G&W is actually...pretty scary now. Good shield, l-cancel all his already good aerials. His smash attacks were kept the same as they were in brawl (and they were both strong and spammable in brawl so that's scary). Uthrow chaingrabs with a dthrow tech chase option really...? His dtilt combos but at the same time has the brawl range....which is makes it one of the largest moves? They nerfed his recovery, no more parachute.
The thing I noticed overall is that it's a lot harder to shield grab and tech chase people.
I'm sure MK didn't need those nerfs. Only losers don't DI the tornado. It's actually pretty easy to punish at high level of play. It's used more as a safe recovery option since it has so much priority and "chip" damage / shield pressure though some characters like diddy kill that asap