Having replayed the game, the score is insane, regardless of what they gave the original.
The level design here is simply on another level. The amount of creativity on display and variety is amazing. Too good for it to be dragged below an 8 by dumb shit like "you lose your power up when you die" or "multiple people can't pick the same characters". Stuff like that is the difference between a 9 and a 9.5, not the difference between a 7 and a 9.
My biggest complaint is that the controls just don't feel as tight as in other Mario games. It was designed for players to be able to play it with a Wii-mote originally, so the controls were compromised, You have an 8 way run, which works fine most of the time because the levels are designed mostly around this. But in the few occasions where you need more subtle control, it feels off. Also, the momentum based running system is so awkward compared to other 3D Marios.
Still, the game is great. I like the more linear style of Mario 3D, and whereas 3D Land was fun and basic, this is them really pushing the envelope. 3D World is worthwhile (if you don't have the Wii U version) on its own. Bowser's fury is much more meaty than I thought. I think it's be a good 5 hours if you were only looking to see the credits. I think I'm something like 10 hours in trying to get every cat shine. It feels kind of like they took ideas that were left on the cutting room floor and strung them together into an open world setting. It doesn't feel as cohesive as something like a world in Galaxy and each of the islands kind of lack identity. But it's still a fun diversion and the kaiju battles are fun if again a little half baked. Would have really been nice if they had true co-op play, and maybe a few new power ups and gimmicks (aside from Giga Cat) to play around with rather than sticking to what was found in 3D World. It's mostly more of an already good thing, which is fine. If it were 15 dollar DLC, it'd be a solid 8/10.
The whole package I would rate probably a 9.5. The core of Mario 3D World is really amazing due to the level design which is the most important factor in a platformer by far. The control issues, and some of the minor flaws (game not always feeling well balanced for multiplayer, lackluster boss fights, and I may be in the minority but I think the Cat powerup is one of the less fun ones in Mario history and wish it was emphasized less) would bring it to around a 9, but Bowser's fury nudges it back up a little.
The only problem is that if you were a Wii U owner, you've likely played this before, and it kind of sucks that you have to rebuy the whole package. I enjoyed playing 3D World again, but even with the minor tweaks, I think I'd still have opted to replay it on the Wii U and pay 15 bucks for Bowser's fury if that were available. Maybe I'll feel different when the pandemic is over, and I have a commute again.