G.I. Joe: War on Cobra 1.2.8 Release Notes – 

What’s New in this version of G.I. Joe: War on Cobra?
– Two new units added for you to unlock: Medi-Viper and Guided Missile, along with a new event!
– Reduced the HQ health for Joe and Cobra
– Increased Damage output of VAMP, Gung-Ho, Outback, Missile Barrage for Joe
– Fixed several frequently requested bugs (including units getting stuck moving, random disconnects after battle, sea battles appearing too early and disconnected tank traps in the base)