@PurpouHeize:

You're right that Kirby has a decent grab game on some characters, and more than a few useful moves in his kit. Side-B is very powerful but extremely laggy and easy to punish, which makes it not very useful except out of a combo in competitive play. Neutral-B is really useful in some matchups, but not in every matchup and is very punishable if you miss.

The main things holding Kirby back are a lack of mobility (very poor speed and dash length means that he can't maneuver effectively on the ground, and a poor airspeed mars him in the air) and a lack of range.

The reason this hurts him so much is easiest to see if you think about the neutral like this: every character has a range where they can hit you before you can react. For a character like Marth, that range is dash-cancel dtilt or fsmash: really far. That means that even when Marth isn't swinging his sword, the implicit pressure of being able to hit you very quickly means that you have to be extremely wary of him. Fox doesn't have a lot of range, but he still has so much speed that this crucial unreactable-attack range is still large: running SH nair.

For most characters, this crucial zone is a function of both speed and range. Kirby has terrible range AND speed, so the range at which Kirby applies implicit pressure is tiny. That means that you very rarely are scared of what Kirby is about to do and can usually deal with whatever he does. Even matchups where Kirby has a brutal punish game and is considered to win the MU (Kirby-Fox) can sometimes be dismantled by extremely patient play. Kirby has good defensive tools, but he can't really approach effectively, so just sit back and make him come to you and he struggles immensely.

Of course, once you hit Kirby another weakness becomes apparent: his lack of a good combo breaker means that many characters like Marth can deal lots of damage in punishes despite Kirby's weight and falling speed, and his lack of survivability means that characters like Marth get extremely quick kills out of combos like fthrow -> fsmash.

Combined, this means that while Kirby has good matchups against some characters that have trouble dealing with Kirby's small size, priority, and edgeguarding ability (Falcon, Fox), he has extremely difficult matchups (70-30 or worse, some of the worst in the game for anyone!) against characters like Marth that can abuse Kirby's lack of implicit pressure and projectile options to slowly dismantle Kirby in the neutral and abuse his lack of combo breakers and poor survivability to make each hit count for a lot. He's not unviable or anything, but he struggles a lot in a few matchups, making him a much tougher solo main than the vast majority of the cast. (He's actually a pretty good secondary with a character that can handle his bad MU's and appreciates Kirby's MU versus fast fast-fallers).


Sora-Kirby is an extremely challenging pair of mains! They both struggle so much against Marth and Lloyd (two of the most-played characters), and this means that they really don't cover each other's weaknesses at all. Every character is viable in SSF2 so there's nothing stopping anyone from doing that, but I'd recommend if someone were trying to pick two characters to main in tournaments that you pick a character that handles range well (Fox, Sheik, Marth, Pikachu sorta, Falcon for dealing with Marth, ZSS, etc.) so that even if you then use a character as your primary main that struggles with range (Wario, Kirby, Sora, Zelda, Puff, etc.), you aren't forced to play bad matchups over and over in tournaments.

Every character is viable, it's just that some have it easier than others.

Also, Chibi Robo has a decent matchup against MK (iirc about 60-40? Or 55-45? Maybe even 50-50 but I highly doubt it)

Didn't Kyoz win a tournament with Chibi?

I think every character could win any tournament. It's perhaps unlikely, but not impossible.

The other thing to keep in mind is that once you get to the upper echelons of the SSF2 scene, it's far more about players than characters. If you look at the earlier tier lists, they're dominated by Kyoz and Lunary characters because those were the things winning tournaments. Obviously there's plenty to like in ZSS, but her dominance in the tournament scene wasn't because she was busted, but more that out of the twenty-something characters in the game, most of them in the hands of players who are in their own tier could beat everyone else.