Can you keep playing after finishing the main game?

[zab]

I want to do the DLCs after the main game but I need to know if it's possible or if you can't keep playing after you finish it. pls

[Dr.Vodka]

you can go back and do the dlc portion of the game after beating the final boss at anytime as the game autosaves just before you go into the room and upon loading the save will place you to just before going into the final boss room

[Jethro Minglethorpe]

you can keep playing on a save no matter what

unless its a certain game mode