4P Achievements Guide
This is a very simple guide if you have been having trouble finding people to play with to finish off your achievement boards.
This is referring to the two achievements: Birds Of A Feather, and You Are Hardened. All you have to do is start up a single player match and either get a hat from the multiple places to find them, and\or get to level 30 and defeat the boss on that day, make sure its set to hard-mode cheats also don’t register like they do in a typical 4P co-op match, so feel free to use them all you want.
This also works if you just want to grind days to 101 to beat the game on hard-mode., or anything else.