Sev Zero is available exclusively on Amazon Fire TV. Sev Zero requires a compatible game controller. The game is free with the purchase of an Amazon Fire Game Controller. Sev Zero combines fast-action shooter mayhem with tower defense-style strategic base building. Wield an expansive arsenal of firepower across 15 levels to hold off the alien onslaught that's threatening you and the entire planet. In Sev Zero, players can jump between environments - start in tower defense mode to build out towers and assess the surroundings, then beam down to shooter mode for face-to-face combat.