I read that this game is pretty fucking good? Also, how's co-op online?
I played the game in co-op till the end so I will reply you.
At first glance, co-op seems cool but there're flaws that annoyed me.
What annoyed me is my experience out of combat because I didn't had much freedom.
Examples :
1) There're a lot quests which trigger dual dialogs only if you're close to each other.
These dialogs can give you bonus stats.
2) Following a conversation in live is not possible for the player who didn't talk to the npc. He will need to either read the chat or the log chat (in the journal). It becames really painfull after the first zone for us and I kinda asked my mate to resume me what happened. So that didn't helped me to get into the story, imo. I would've prefered something like in Diablo 3, the other player if close can read the dialog too in live.
3) Exploration... only in cities we could separate a bit to searchthe surrounding because outside we we had to stick to each other since the battle exp is not shared if you do not particpate in combat. While in Diablo 3, if second player is on the map, he can receive exp. Some people will say, that battles without 4 characters is hard so separatiing the team is not really an option, that's true. Still, it would've been nice to share exp, imo.
The last thing is, I couldn't save the game. It's the host who can so if I wanted to try something dangerous on by own, I couldn't save and I had to ask my friend everytime to do it (o yeah and your inventory close when he do it). Not really cool when both us were trying to explore rooms full of traps, lol. I know that in Baldur's gate 2, host can give option to second player to save and even pause the game or help manage inventories.
In the end, I felt more that I had a leash to my partner and same for him, outside of battles. But thanks to battles, we had a lot of fun together.
I'm sorry for my bad english.