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An armored marine and a combat drone hold a shielded platform while a huge tusked alien boss charges across a purple wasteland.

Sector Defense

The aliens took the world. You hold the line, one sector at a time.

Deploy freeAndroid now, iPhone soon

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Free on Google Play from September 30, 2026Single-player, no PvP13 languages

Sector Defense is a free sci-fi tower defense game for iPhone and Android with a roguelike upgrade draft. You play the marine on the front line: move left and right to shoot forward while combat drones fight beside you, pick new tech as the alien swarm closes in, and take back the map sector by sector, from scorched desert to frozen arctic.

What happened to the world?

  1. When they came, everything changed in just a few moments.
  2. I watched our cities fall as the enemy took over our world.
  3. We needed an advantage. So we built combat drones.
  4. We know which places we need to take back.
  5. Now the sector defense begins. And I'm on the front line.

The opening lines of the game, as your marine tells it.

How does a run work?

You don't place towers and wait. You are the defender, on the line, and your arsenal grows mid-fight.

  1. Hold the line

    The swarm comes down the sector toward your wall. Move left and right and your marine shoots forward; the Sentinel drone fires alongside on its own.

  2. Pick your tech

    Kills fill your XP. When it's full, the fight pauses on a Tech Choice: a new drone weapon, an upgrade, or an elite tech that changes how a weapon fires. Spend Dice to reroll the offer.

  3. Take the sector

    Survive every wave and the sector is yours. Your hero, gear and research carry over to the next sector, and the map pushes on.

Tech Choice · XP full

Interactive illustration, not the live game

Pick one. It joins your drone for the rest of the run.

Drone loadout

  • Empty slot
  • Empty slot
  • Empty slot

What do you fight with?

Your marine carries one main weapon. Drone weapons arrive during the run, and every hit carries an element, Fire, Electric, Toxic or Void among them. Here's a first look at the arsenal.

Main weapons

Assault Rifle
Rapid-fire rifle effective against all enemy types.
Pyroblast
Rocket that explodes at the first enemy and can apply Burn. Aimable.
Lancerion
Main laser built for extreme penetration and precision.

More main weapons wait further into the war.

Drone weapons

  • HellfireExplosive burn
  • ChainlightRicochet shock
  • VenomSlow and vulnerable
  • Rift OrbPiercing rebound
  • HornetHoming rockets
  • And moreDrafted mid-run

What are you up against?

The swarm comes in classes. Light creatures come in numbers, heavies soak fire, elites breed and snipe, and the bosses break walls. These are the ones you meet first.

Mordax, a boss alien

Mordax

Boss

A colossal armored beast that tears through defenses with its massive tusks.

Vorgath, a boss alien

Vorgath

Boss

A towering brute that crushes defenses with devastating melee attacks.

Light

  • Skitter

    A small, fast creature that attacks in large numbers.

  • Shrike

    A swift flying predator that attacks from the air.

Medium

  • Spitter

    Attacks from range by launching toxic projectiles.

  • Burrower

    Burrows underground, becoming untargetable while moving beneath the surface.

Heavy

  • Crusher

    A massive, durable creature capable of absorbing heavy fire.

  • Broodworm

    Emerges from underground and continuously releases Skitters until destroyed.

Elite

  • Matriarch

    An elite breeder that releases a swarm of Skitters upon death.

The deeper you push, the stranger the swarm gets. Not every contact on the map has a name here.

Who's on the line with you?

A roster of heroes, each tied to an element, plus the gear, gems, artifacts and walls that make your defense yours. Meet a few of them.

  • More to
    recruit

Garrick Voss

Metal element

His father died protecting him during the first invasion. Now he believes the broken world can still be rebuilt, one order at a time.

Heroes
A roster of heroes to recruit, each tied to an element and a fighting style. Hero contracts raise their star level.
Gear and gems
Armor, helmets, gloves and more to equip. Gems socket into gear and merge into stronger ones.
Artifacts
Relics like the Plague Mask, the Lucky Paw and the Titan Heart, each a permanent bonus.
Walls
Perimeter walls to raise around the colony, among them the colonial Ironhold and the Nullgate, built on forbidden Void tech.

Where do you fight?

The campaign takes you sector by sector through alien-held biomes, from the desert to the frozen arctic. Clear it and Heroic mode is waiting.

  1. Desert

    Defend the desert area.

    HOSTILE-HELD

  2. City

    Protect valuable resources.

    HOSTILE-HELD

  3. Arctic

    Defend the citizens of the Arctic zone.

    HOSTILE-HELD

  4. Under fog

    Not every sector is on this map yet. Push on and find out what's out there.

    ??

Beyond the campaign

Heroic mode
Waiting for players who clear the campaign. Think you've seen what the swarm can do? Heroic mode says otherwise.
Gas Tunnels
Clear the areas and destroy the nests for rare resources. The deeper you go, the worse it gets, and something far bigger lives down there.
Daily challenges
Fresh challenge stages every day, plus leaderboards for enemies slain and tunnel progress.
Events and passes
Rotating events and a Battle Pass with their own reward tracks.

Your base, even offline

Your base keeps mining while you're away: resources pile up offline, up to the maximum mining time, and wait for you to collect them. Auto-pick tech and auto next sector let the game play on when you'd rather watch.

Energy Core
Energy is processed here. You can't go on a mission without it.
Crystal Mine
Processes the crystals that enhance your equipment.
Laboratory
Runs the Research Tree between missions.
Command Center
Dispatches your hero on special challenge missions.

Expand the base and new facilities unlock as the colony grows.

What does it look like?

A 23-second trailer and the store screenshots, straight from the game's listing.

Questions from the field

If you like tower defense, roguelike survivors, alien-swarm sci-fi or RTS marines holding a choke point, Sector Defense sits where those overlap.

What is Sector Defense?

Sector Defense is a free mobile tower defense game with a roguelike upgrade draft, set in a sci-fi war against an alien swarm. You play the marine on the front line of a sector: move left and right to shoot forward, fight beside combat drones, and pick new tech between enemy pushes. It is made by NOXGAMES for Android and iOS.

When does Sector Defense come out?

Sector Defense launches on Google Play on September 30, 2026. It is built for iPhone and iPad as well.

Is Sector Defense free to play?

Yes. The campaign is free to play. The game has optional in-app purchases and ads.

Which phones does it run on?

Android phones and tablets running Android 7.1 or later, and iPhone and iPad running iOS 15 or later. It plays in portrait.

How is it different from other tower defense games?

You don't place towers and watch. You are the defender: your marine moves along the line and shoots forward, drones fire alongside, and the weapons you fight with arrive mid-run as Tech Choices. Every run builds a different loadout, and element matchups matter more than placement.

What are the aliens?

The swarm includes Skitters that attack in large numbers, flying Shrikes, Burrowers that go untargetable underground, Broodworms that keep spawning Skitters and elite Matriarchs that breed more of them. Bosses like Mordax, a colossal tusked beast, and Vorgath, a towering brute, break walls, and there is more out there than the first sectors show.

Is there a lot to play?

Yes. The campaign pushes sector by sector across very different biomes, from the desert to a ruined city and the frozen arctic. Clearing it opens Heroic mode, and the Gas Tunnels, daily challenges, events and a Battle Pass keep adding more.

Which weapons can I use?

Your marine carries a main weapon, such as the rapid-fire Assault Rifle, the Pyroblast rocket or the Lancerion laser. Drone weapons arrive during the run as Tech Choices, among them Hellfire rockets, Chainlight arcs, the Rift Orb and Hornet homing rockets, and there are plenty more to discover.

Does Sector Defense work offline?

Your base keeps mining resources while the game is closed, up to the maximum mining time, and they're waiting when you come back.

Is there PvP?

No. Sector Defense is a single-player game, with leaderboards for things like enemies slain and Gas Tunnels progress.

What languages is it in?

13 languages: English, Czech, German, Spanish, French, Japanese, Korean, Polish, Portuguese (Brazil), Russian, Turkish, Ukrainian, Vietnamese.

Who makes Sector Defense?

Sector Defense is developed and published by NOXGAMES s.r.o., an independent mobile game studio based in Brno, Czech Republic.

How do I contact support or report a bug?

Use the support form on the Support page or email support@noxgames.com. Include your player ID if you have it, so the team can find your account faster.

The map is theirs. You start at sector one.

  1. Desert

    01

  2. Under fog

    ??

  3. Under fog

    ??

  4. Under fog

    ??

  5. Hostile

    ??

The campaign map: you land in the desert at sector 01. Everything past it is under fog until you take it back, and Heroic mode waits for those who clear the campaign.

Free on Google Play from September 30, 2026. The iPhone version is on its way.

Deploy freeAndroid now, iPhone soon

Writing about the game? The press kit has the fact sheet, logo and art.