I guess I'll start by talking about Kraken Royale. At first I'd thought it would be pretty bad as I would've thought Nintendo would be very cautious about bringing back the most contentious special back in 1 over to 3 and overnerf it as a result. However in reality, it's pretty good I feel. I can't say it's the best special in the game, but at least it's not awful. In fact, I think it's very fun to use. They managed to get rid of what made it frustrating to fight against, for the most part, and still made it feel fresh with the new Kraken Surge. I'm very pleased with how Kraken turned out overall.
As for Super Chump, yeah it's uhh … well it kinda sucks. The fact both weapons have its cost at 180p was an immediate red flag to me. It doesn't provide much of a threat with its weak damage and can be destroyed easily as its also paper thin. At least it doesn't have much commitment to use and won't get you killed in the process of using it - unlike Zipcaster or Reefslider - so at least it has that going for it. Also to add, both NZAP '89 and Clash Neo had Tenta Missiles back in Splatoon 2. Just some food for thought. Speaking of which, we haven't seen a new Tenta Missile weapon since release, or even a new Crab Tank weapon as a matter of fact.
I also just want to go on little tangent about Neo Splash-o-matic for a sec. Now I know why it has that kit because it's an analogue to Vanilla Splash from Splatoon 1. Even so, we didn't need another short-ranged shooter with suction bombs. Also with Triple Inkstrike you might as well not have even bothered making Tentatek in the first place. You could have at least give it Ink Storm instead as it would separate it from the other shooters while still being similar to its original paint-focused kit. Oh well, it doesn't matter that much as this is a problem present in all the games to an extent. However it would've been nice for Splat 3 to finally break this mold.
On a lighter note, getting Inkopolis plaza back is neat. Granted it's nothing more than a novelty, but that's fine by me as someone who started with Splatoon 1. Would have liked to seen the original testing range back though.
A jukebox feature added to the game finally allowing you to change the music. Only in the battle lobby.
C'mon Nintendo, you were sooo close. Just go a little further and let us be able to change the music in matches too.