It took me about 55 hours and at least a third of that time was spent managing the inventory and rearranging hotbars because they don't fit enough spells.
If I'd know how much of a hassle Crafting would be and how unnecessary it really is, I would've avoided collecting all that garbage, thus easily shaving off another 10 hours.
Realistically, there is about 40h of gameplay. Depending on how much time you wanna spend optimizing your gear through whatever means you can drag this out, but again, it's pretty unnecessary, the game gets really easy after lvl 12. If you follow a build guide and don't end up with one completely useless main char like I did you can breeze through fights.
