Mission: Aliens

Sergeant, last night we received a signal that an unknown aircraft of extraterrestrial origin had crashed in the taiga. The locals assured us that at the crash site they observed five creatures very similar to humans, only with gray skin and large almond-shaped eyes. The locals said that a group of people and a lot of military equipment quickly arrived on the site, they collected every shard of it and fled. Your task is to sneak into the base, to eliminate all the guards and release our brothers in mind. Then you'll just have to leave the territory of the base and return to headquarters. Is that clear? Execute. The main mission of the game is to release five aliens that are locked in cells, and to release them each cell needs an individual key. After you save everyone, you need to get to the exit and save yourself.