The first round of DLC has been released on the Steam store. Weapons, camp themes, music, in-game wallpaper and various costumes to choose from. More to come later this month.
Just released DLC:
SPECIAL COSTUME PACK 1 & SPECIAL WEAPON
SPECIAL COSTUME PACK 2
OLD COSTUME PACK 1
OLD COSTUME PACK 2
OLD COSTUME PACK 3
OLD COSTUME PACK 4
POWERFUL WEAPON PACK
UNIQUE WEAPON PACK
BASE THEME PACK
BGM PACK
WALLPAPER PACK