Love:
- Overall character balance. Not perfect, but the best Smash has ever seen.
- Elements communicated intuitively by visual effects (white flash with L-canceling, red/yellow overlay during Bowser's armor frames)
- Generally very professional and well-made.
- A lot of care given to match hitboxes and animations
- Brawl newcomers mostly well-designed and natural-feeling
- Roy and Mewtwo
- RAR is oh-so-nice in a Melee-esque environment. Pivot grabs, too.
Hate:
- Too many similarities to Melee. Doesn't feel "new."
- The overall design philosophy of making things match Melee for no reason other than to match Melee
- Lucario. He's by far the worst-designed character. Aura charges are cool (I'd like to see all characters have them in the form of "EX Specials" or something), but OHC is a garbage mechanic that is a special case that doesn't intuitively fit the natural forms of the game.
- Zelda and Sheik together. Split them and give them full movesets. Making both of them individually viable means that they are going to be far too good together.
- Ice Climbers. I get that they are all about grabs, but it's such poor design. It's all finger dexterity and zero actual gameplay or strategic depth.
- Some characters are too polarizing. That is, they have very few, very powerful options that dictate their play style (Jigglypuff and Rest), and all of their other moves serve to work with those few options. It reduces the potential for diverse playstyles and player expression.
- Samus. Super Metroid came out almost 20 years ago, so let's modernize Samus. She's no longer super floaty and robotic, she's very fast and athletic. I'd like to see her aerial physics matched to Other M and Zero Mission, because the platforming in those games was absolutely sublime and would work so well with a modernized Samus. Two beams are cool, but it's a bit of a special case gimmick. I'd like to see the ice element dropped altogether, and her default fair and upsmash changed to her ice beam varients; they'd just work better with a more nimble Samus. Also, the super wave dash. The technical barrier is stupid, it's a special case, and it's glitchy and unprofessional. Just give her better mobility.