Okay, so I tested the demo yesterday, and here are my impressions. First I'd like to just say that this was the e3 demo and not "demo 2", so I can't really have a "demo 2 Pac-Man" point of view, as I don't know what have changed from demo 1 to demo 2. With that said, I only got to play a few matches, like 10 at most, and it is kinda hard to form a solid opinion/impression of a character when you didn't had so much time to spend on it, yet alone the game itself... Furthermore, playing Smash with a Pro Controller was kinda weird, so combined with the game being new, it was hard to do some inputs and such. (Grabbing and tap-jump on, for example.) Other game specific things like how DI works and whatnot also makes things harder to gauge, but in the end I think I have just enough experience to form a personal opinion/impression on him.
Yeah, Pac-Man just sucks. Not only did they heavily nerf his Bonus Fruit, but his new up-tilt is complete trash as well (compared to his old one). Even then, his up-tilt isn't that good. (Honestly, it isn't.) You would think it is kind of like Mario's up-tilt, which scoops up the target and hits in front of him, but nope, Pac-Man's up-tilt is not like that. The hitbox is tiny and hard to hit with. Think of it as Pac-Man's up-smash, but without the scooping hitbox, and a much smaller hitbox. It feels like if you can up-tilt, you can just up-smash instead... Though I think if you catch people with it, you can juggle them for a while or create favorable situations. But the biggest draw to it is that you can't hit the Hydrant with it when you stand next to it... Speaking of Hydrant...
Oh boy. When standing next to it, you actually get pushed away from it, meaning they really don't want you to be able to up-tilt it. (Not sure if up-tilt would of hit anyway, because of its tiny hitbox.) It also felt to be dropping slower in the air and have more lag when dropped, even on the ground.
His up-special is nerfed too, which I predicted. It appears as if opponents now can power shield ("parry") it on the ground, without getting on the trampoline. (They are blocking Pac-Man's up-b hitbox.) When someone was sitting in shield, I ran up to them and used up-b on their shield, but the power shield effect triggered and they didn't bounce on the trampoline. It happened at least once to me. However, not everything is bad with the trampoline itself - it is great that it has a hurtbox now. When turned green, we all know that opponents will enter free fall from it. But Pac-Man won't, and I actually tested this! It acts like a yellow trampoline for him, turning red when he bounces off it. So that's cool!
I want to talk about his fruits a little: Cherry and Strawberry now have more active frames in the air. Same with Apple. Bell seems to stun people like 10-15% longer, but I'm unsure of it. But it felt like they were in stun longer. However, I barely had the time to connect a fully-lengthed Power Pellet to an opponent at around 100% or so, so maybe it is the same duration as in Smash 4. Galaxian and Melon seems the same to me. Same with Key. It really sucks that Melon is as weak as in Smash 4, same with Key. I hit an Inkling to 130% with the Key and Inkling didn't get KO:ed. A real bummer. But I have forgotten a fruit now, haven't I? Yes, the Orange. It really sucks. It's the most nerfed out of them all. It travels slower, disappears sooner and is much weaker. It's such a shame. It is awful.
I can confirm that Bonus Fruit doesn't stale and that you can pick it up after it hits someone/something, just as you could in Smash 4. When Z-dropping a fruit, it behaves the same as it does in Smash 4, only this time you can't pick it up. That is really unfortunate.
His Bair and Up-air are still weak (the former couldn't KO at 130% and the latter couldn't KO at 150%), I hope this is fixed in demo 2, otherwise it is going to be just like in Smash 4. His Dair however... Haha oh boy, it is really good, especially on bigger characters! It was definitely my favourite aerial of them all! It can be used in the neutral much better now and can actually lead to stuff depending on their DI. I managed to get dair to key two times, though it is hard to say if it's guaranteed. I also managed to get one dair to dash attack, but all of this Dairing needs more experimenting. His nair is nicer and fair was harder to string together, though I believe it can lead to stuff much earlier now, even the infamous fair to key.
Out of all smash attacks, his down smash stood out the most. They've really nailed it this time! It is quicker, stronger and a little bit safer now. It is a potent and legit kill move now! Finally!
His backthrow is a kill move at higher percentages now (unlike in Smash 4) and I don't even need to comment on his grab. (The hitboxes are better, no deadzones, the hand has a hitbox and it seems to have a faster start-up as well, probably frame 9-10 I believe.)
All in all, I still think Pac-Man has a long way to go to become a viable character. As I said before, I don't know what has changed about him in demo 2, but in this demo he is still trash. Not as trash as Smash 4 (bottom tier trash), but low tier trash at best. (Though I still think he is bottom tier in this demo.)
Here's hoping he becomes much better in the release version.