I thought the game was good overall but has its flaws.
First 2 acts were awesome, especially act 2. Felt like there was a ton to do, a bunch to find, and you always knew what to do.
The last 2 acts were pretty horrible in comparison, I think. When you're on the island in act 3 or whatever, it's just... short.
Act 4 was the worst quite easily. Half the time you don't know what to do, the other half you simply don't know where to go or what you need to do next. Barely any of the quests have markers so you're basically left to wander most of the time. The quests themselves felt pretty weak. Just a bunch of fighting, essentially, against stuff that has a ton of HP.
The final fight was a surprise in terms of the bosses but the fight itself was absolutely ridiculous. Not sure if it was just me but it felt damn near impossible and took me hours and multiple sit-downs after rage quits to finally beat it.
Overall I'd give the game an 8/10. If the entire game was like the first 2 acts it'd be an easy 10/10 but they dropped the ball pretty hard I think.