https://www.gamespot.com/articles/call-of-duty-ww2-adds-gun-game-and-prop-hunt-modes/1100-6457208/

Call of Duty: WWII has added two new modes to the roster of permanent playlists. Originally released only for a limited time, the fan-favorite Gun Game and Prop Hunt modes are now available permanently in the multiplayer shooter on PS4, Xbox One, and PC. 

In Gun Game, you start with a pistol move up with every kill. Getting killed with a melee attack sets you back a tier. Prop Hunt, meanwhile, is a more casual, party mode where players on one side are disguised as map elements like a sandbag or a barrel while the other team hunts them down.