The game is a tower defense in which you lead a faction in the evacuation of Greenport, the main city of Plum Island that is now infested with zombies. You manage your group at a tactical-level, moving each unit independently.
This game is most likely the Beware the Shades! title that Luttmann was teasing us about in his interview from the very last days of 2020.
It is currently available for a P-500 pre-order, and you will find plenty more information on that page.