Comparison

Perimeter Zero vs Sky Shield

Price, ratings, monetisation and update history for both games, side by side โ€” with what reviewers say about each.

Head to head
About

Perimeter Zero

Features
Read full description

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 โ€” 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 โ€” 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 โ€” 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 โ€” 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 โ€” 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 โ€” fully optional, and the game works completely fine if you're signed out. Build the perimeter. Watch the coverage. Hold the line.

About

Sky Shield

Features
Read full description

Sky Shield: Missile Defense is a modern arcade reimagining of the classic missile-defense genre โ€” tap to launch interceptors, detonate them in the path of incoming warheads, and keep your cities standing wave after wave. THE CORE LOOP Missiles fall from every angle. Your silos have limited ammo. One well-placed blast can chain into two, three, or more kills at once โ€” precision and timing matter more than reflexes alone. โ€ข Tap anywhere to fire โ€” your nearest silo always responds instantly โ€ข Chain explosions into multi-kill combos for bigger scores โ€ข Six cities to protect โ€” lose them all, and it's over โ€ข Escalating waves bring faster missiles, split warheads, smart-tracking threats, and enemy carriers โ€ข Leftover ammo carries a bonus into your next wave โ€” efficient defense is rewarded, not just survival BUILT FOR REPLAYABILITY โ€ข Bonus city reserves let you recover from a rough wave โ€ข Watch a short ad to reclaim a lost city mid-run โ€” always optional, never required โ€ข Chase a new personal best every run, with your full high-score history saved on-device โ€ข Play fully offline โ€” no wifi, no login, no waiting A LOOK OF ITS OWN Sky Shield trades pixel-art nostalgia for a clean, glowing night-sky aesthetic โ€” cyan interceptors, warm missile trails, and a soundtrack built for tension. Simple to learn. Hard to master. How long can you hold the line? Privacy Policy: https://skyshield.bysupa.app/privacy Terms of Use: https://skyshield.bysupa.app/terms Support: https://skyshield.bysupa.app/support

Screenshots

Perimeter Zero4 screens
Sky Shield4 screens

Verdict

The call

The clearest difference is iOS requirement: Perimeter Zero at 16.0 against Sky Shield's 26.2. On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Perimeter Zero sells 1 one-off in-app purchase and Sky Shield sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Scorecard1 real difference ยท 5 level
Perimeter Zero versus Sky Shield: the parameters behind the verdict, then further details
ParameterPerimeter ZeroSky Shield
PriceFreeFree
Update frequencyEvery 2 daysโ€”
AdsYesYes
In-app purchasesYesYes
DevicesiPhone, iPad โ€” betteriPhone
Requires iOS16.0 โ€” better26.2
Further details โ€” not scored
Size11 MB16 MB
Age rating9+12+
DeveloperHyacinthe LouaAndre Grillo

In-app purchases

1 purchases

Perimeter Zero

One-time1
  • PerimeterZero Premium$2.99
1 purchases

Sky Shield

One-time1
  • Remove Ads$2.99

Questions

Is Perimeter Zero free?
Perimeter Zero is free to download, with in-app purchases available.
Is Sky Shield free?
Sky Shield is free to download, with in-app purchases available.
Do Perimeter Zero or Sky Shield have ads?
Both Perimeter Zero and Sky Shield show ads.

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