Halo 3: ODST

This 1st person shooter video game was developed by Bungie and released on September 22, 2009. The players assume the roles of Orbital Drop Shock Troopers (ODST) who are elite human UN Space Command soldiers. A number of alien races called the covenant attack earth as the player explores the ruined city to unveil what became of the missing teammates who were separated from each other at the city entrance. The player controls a lone UNSC soldier called Rookie. When there is damage, the screen flashes red, where the player gains health by resting or by medipacks to restore permanent health, it flashes green.