It seems jolly unlikely that Capcom will bring their Monster Hunter series to PC any time soon, but if you really want to hunt giant nasty things and beat them up in half-hour boss battles, Koei Tecmo will let you have a crack at their knock-off.
Toukiden: Kiwami [official site], an action-RPG about hunting and murdering giant demons, is coming to PC via Steam on June 26th. It's all a bit Monster Hunter-y but I hear it's not as good as Monster Hunter but you do get to fight giant demons and it does support co-op and that doesn't sound half-bad.
Right! So: hordes of horrible demons/oni have swarmed the world, and you're one of the defenders of your village. As well as smashing monsters yourself, you can become pally with other warriors in your village and have them join your squad. Or replace them with online co-op players.
As these sorts of games often will, it boasts of big numbers: 100 hours to complete; 50 types of Oni; 300 fallen heroes "whose rescued souls help strengthen the player’s team", which I'm sure means something; and 1500 weapon variations.
Toukiden: Kiwami is made by Dynasty Warriors and Samurai Warriors and All The Warriors developers Omega Force. It came out on PlayStation 4 and Vita in March, so this release isn't too far behind. As the one PC trailer is rubbish, here's one for the PS4 version: