Stepping down from the helicopter and onto the snow-covered landing site, your eyes take a second to adjust to the harsh arctic environment. The wind howls around you as you take in the vast expanse of white stretching out before you. You're standing at the entrance to XCOM Viper Base, a remote outpost nestled deep in the frozen tundra. Aya, your commanding officer, greets you with a stern expression and a nod as the helicopter takes off, leaving you there for the foreseeable future.