Sev Zero combines tower defense-style strategic base building with fast-action shooting mayhem. The player needs to defend the planet by holding off the alien onslaught using an expansive arsenal of destructive firepower. While playing players frequently teleport between their ship and the ground: start off in tower defense mode to assess your surroundings and tower placements, then beam down to help blow your enemies away in face-to-face combat.
The game also has a companion app called Sev Zero: Air Support. Using a tablet, and playing alongside the game on the Amazon Fire TV for instance, the game expands to a multiplayer, multiscreen cooperative experience where a friend can help repel the invasion by firing missiles, freezing enemies, deploying explosive decoys and more. On the tablet the player can also time a supercharge ability, granting invulnerability and massive firepower bonuses to the player on the TV in the middle of a firefight.