OneShell has been removed and Headshot is now Mixed Mods which has 5 different mods:
Normal HS - Otherwise normal but headshot is kill.
HS only -- Only headshots kill.
One Shell -- You start with luger and with one bullet. With every kill you get one bullet and from sprees also one bullet. (Sprees at 3, 5, 7, 10)
Last Man Standing -- Teams play rounds and everyone has one life per round.
Stopwatch -- You do objective in Aldernest and Supply and other side defends. Respawn time is 30sec, no double jump.

Every mod has 2 maps then comes the next mod.