Sadly, no. The Resident Evil 4 remake remains a completely single player experience just like the original. Despite there being numerous instances where Leon is accompanied by NPCs, mainly Ashley, there is never an option for another player to take control of her or any of the other characters. This is one mission you will need to handle by yourself. The only possible way co op could potentially come to the Resident Evil 4 remake is via the yet unreleased Mercenaries mode. Originally, this mode...
