Star Fox Guard is a tower-defense spinoff bundled with — or sold separately alongside — Star Fox Zero on April 21, 2016. Originally pitched as Project Guard at E3 2014, Star Fox Guard puts you in charge of a network of 12 surveillance cameras protecting Slippy's mining colony from waves of robotic invaders. It's short, weird, oddly stressful, and the only Star Fox game where you never pilot anything.
Star Fox Guard's setup is unlike anything else in the series. You watch 12 camera feeds simultaneously on the TV, with the Wii U GamePad showing a tactical map. Robotic enemies attempt to reach a central reactor; you switch between cameras and shoot the robots with each camera's mounted laser before they get past you. As missions progress, decoy robots, EMP units, and shielded enemies force constant attention to all 12 feeds at once. It's tower defense by way of an ATC simulator.
Star Fox Guard takes place in Corneria's mining belt, where Slippy Toad's uncle, Grippy Toad, runs a robotic mining outfit that keeps getting raided. Fox and Star Fox cameo briefly between missions but never appear in gameplay. The connection to the rest of the series is thematic at best — but the Slippy family expansion has been a fan-favorite curio.
Star Fox Guard scored in the mid-60s — slightly above Star Fox Zero, but well below the Star Fox mainline average. Most reviewers acknowledged that Star Fox Guard is genuinely well-designed for what it is, just clearly a tech demo for the Wii U GamePad's secondary screen rather than something most players bought a Wii U for.