Perimeter Zero

Build your security operation, survive dynamic night threats, upgrade your command network, and take on daily contracts. Optional Premium removes ads.

Perimeter Zero is a tower-defense game about running a private security operation, not casting spells. You're the commander: place cameras, lights, gates, guards, drones, and a growing arsenal of detection and response tools, then hold the perimeter as intruders test every gap in your coverage. See your coverage, not just your budget Every camera, sensor, and guard shows its real detection and response radius before the night starts. Placement isn't guesswork — you can see exactly where your perimeter is strong and where it's exposed, then build accordingly. A loop that tests you, not just your equipment When multiple threats hit at once, you choose which guard responds to which — a deliberate call under pressure, not an autopilot response. Detection, response, and slowdown layer together into real tactical decisions across cameras, lights, gates, K9 units, thermal towers, cyber nodes, and more. 22 contracts, from a starter warehouse to a national command network Start small with a two-door warehouse. Escalate through delivery depots, tech campuses, research labs, data vaults, airports, harbors, stadiums, hospitals, banks, and eventually a combined national command-network finale — each with its own threat mix, layout, and pressure. Nine intruder types, each demanding a different answer Prowlers, runners, saboteurs, hackers, insiders, credential thieves, vehicle crews, crew bosses, and stealth infiltrators all pressure your perimeter differently. Layer detection and response so nothing slips through unseen. Permanent progression that matters Spend contract earnings in the Upgrade Lab on sixteen permanent upgrades across four specializations — Perimeter Core, Command & Intel, Response Teams, and High-Security Ops. Every contract makes your operation stronger for the next one. Daily operations and mastery A rotating daily contract with its own modifier keeps every return trip different. Chase mastery stars, best grades, and win streaks across every site you've cleared. Fair monetization Banner ads appear only on menu screens — Home, Contracts, Upgrades, and Results. Active night gameplay is always ad-free. A single one-time Premium purchase removes ads entirely and adds no gameplay advantage; Restore Purchases is available anytime. Game Center support Leaderboards and achievements track contracts cleared, best cash hauls, daily streaks, and threats stopped — fully optional, and the game works completely fine if you're signed out. Build the perimeter. Watch the coverage. Hold the line.