E.U.N. Secret Military Base

Hi there,
The war between the E.U.N. (Earth United Nations) and the aliens have been continuing for decades.
The human forces have secret military bases around the globe where they develop weapons to fight the alien invasion but also to study and understand alien technology from captured alien spacecraft and robots in hope of using them against their creators.
The second concept shows some alien mutants infiltrating one of E.U.N secret military bases.
Have a wonderful day!
_KN