Bluntly put, post-apocalyptic Swedish RPG Krater was in rough shape at launch, but as far as I can tell, it's reasonably well off now, and even moreso as of today, as the first bit of free co-op DLC has launched, alongside single player updates. You can see the trailer for said co-op below, though it's mostly CG and...kind of weird.
The new patch includes performance improvements, more single player content, and improvements to the campaign, combat, and character progression. It's said more patches will be released in the coming weeks -- three, to be exact.
Boot the game now to grab the update -- if it's not available now, it will be later today.