Story: It's pretty confusing with the characters just seeming to zip around doing whatever they feel like whenever they feel like and winning most battles purely off of being too stupid to function.
They'll go through things in the game although very out of order and the manga does cross over to both games.
Arcs often end in just a few chapters and can be hard to follow due to the frenetic pace. I will compliment the Emperor arc for having some nice character drama and dramatic tension (even if the motivations following said drama were kind of dumb) although it doesn't really get that serious. It's a silly, silly story. Don't go in expecting it to be any more serious than your average comedy anime.
I also wondered how they would be able to advance after fighting the X rank and second hero campaign. And that is by pulling random stuff from nowhere that's not even in the game as we wait for Splatoon 3 (shadow clones and stamp rallies?? lol.)
Art: Cute, expressive art that translates the characters really well. Very pretty.
Character: A lot of them are total loser idiots and none of them are all that dimensional or fleshed out but I'd be surprised if you didn't find every single one enjoyable. And there are a LOT of characters. Even things you'd expect to be one off battles (ex: the team who hates getting dirty) just keep coming back.
They all have names such as "Goggles" or "Glasses" or "Headphones", most of them are based from the gear they are wearing. You can really see the innovation and creativity brimming from these (not at all stupid) names.
Enjoyment: Despite it's not goodness, I was able to enjoy this a lot. Probably way more than I should have. It's a 5/10 but I enjoy it like it's a straight 10. Plus my humor is broken and therefore I find it very funny.
Overall: Cute and funny manga to turn your brain off to (might end up smoothing it over though). It has more of a fanbase than it probably deserves.