Alright, I've been at it for about 5 hours now, here's what I've got so far.
The game is definitely heavier on the action and lighter on the typical RPG aspects. Don't expect to be building completely different characters, because Elara and Caddoc are who you get. There's only 3 spells and 3 weapon skills for each character, but those can be evolved multiple times and can be tweaked quite a bit (and certain offensive ones can be charged to buff your companion). It does control really well, and certain combat aspects make it a unique experience.
The weapons themselves don't have a lot of differentiation (aside from base damage, speed and meter build) but enchanted ones only hold their enchantments for a certain number of blows, so changing weapons regularly is more beneficial than just finding one really OP one. Shields, which are required to block, have a durability rating and will break if not replaced in time (mid-combat if you're not careful). Luckily, the enemies drop their shields often when you kill them (assuming you didn't destroy it with a spell or well-timed blow).
The atmosphere, voice acting and writing are all top notch, and while it's serious, it never takes itself too seriously. The banter between the to main characters is great, and really keeps you involved when just trekking around. While the game is very linear, there is some exploration to be done, including puzzles placed off the beaten path that actually take some thought to complete (and reward you handsomely).
I haven't tried the co-op yet, nor have I tried any customization with the crucible mode (or unlocked any of the multiple secrets/toggles available in the extra portion of the menu, which I'm very curious about), but so far it has been very solid. If you're looking for something to occupy yourself (and a friend) with, I would recommend it. If you're not starving right now and want to wait for a price drop, you'll definitely get your money's worth. Certainly rent-worthy at the very least.