Finished the game. 85% of the game is excellent. The other 15% is a mix of pretty OK to TERRIBLE.
Specifically:
spoiler (click to show/hide)
The Earth shooter part. Straight up awful in every way. Completely mindless corridor shooting with waves of boring enemies and boring level design. Fire whoever decided to put that in the game.
Everything to do with Last Light and The Ivory Citadel are OK. The puzzles are pretty neat but fighting corrupted angels are a chore and it just feel like it's padding for the sake of it. They reuse a goal from previous in the game where you have to get the water from three sources turned on. Did they think we'd forget about Drenchfort?
Luckily the game manages to end on a pretty high note with two pretty great boss battles.
I have to say that the boss battles in this game were pretty much all really great, actually. I think there was one I didn't like but I can't remember which one. They all were clever and made you do a variety of tasks to defeat them.
The first and second worlds are def the best parts of the game. Going into the last act you feel the pace quicken as the areas you go to are smaller and the tasks are more simple. It's funny tho because that's how most of the dungeons are as well. Usually you have 3 things you need to do and the first two take a while, and the last is pretty quick.
If not for the terrible sections latter in the game this could easily be a shoe-in for GOTY but for not it's just going to be a contender. I'll def go back and do a ng+ if not just so I can take on the crucible and the arbiters soul maze.