Warframe

Warframe is a free-to-play online action game from Digital Extremes. You play as a Tenno, an ancient warrior who controls powerful suits called Warframes, and fight through missions alone or with friends in co-op.

Gameplay mixes fast third-person shooting, melee, parkour and abilities, with a deep progression system in which you unlock new frames, weapons and companions and customize them. The game has a story to follow, open areas and regular content updates. Premium currency exists, but most items can be earned by playing.

The download is the official one from Steam. You need a free Steam account, and the game installs and updates through the Steam app. Steam lists the game for Windows only.