Games like State.io you can play online

This page is written by the team behind Battle of Castles, one of the five games below. We say it here rather than at the bottom. The other games are described from their own store pages, read on 18 September 2026, including the places where they do better than ours.

If you like State.io, you like one simple move: send troops from a territory you own to one you want, and watch the numbers decide. Its Google Play page talks about a "free RTS online" but files the game under "Single player", and says nothing about challenging a friend. If what you want is the same move online, in a browser or on Android, with the option to challenge a friend, here is the short answer:

• Online, free, in the browser or on Android, with a friend mode (1v1 or 2v2): Battle of Castles.
• The planet-to-planet classic, free on PC and Mac: Galcon 2.
• A story campaign plus online PvP, with heroes: Mushroom Wars 2.
• A calm, minimalist game, solo or against friends: Auralux: Constellations.
• Big maps shared by many players: Territorial.io.

Play Battle of Castles in your browser: free, no account, nothing to download.

State.io online: what the five games have in common

All five share the core of State.io: territories that grow troops on their own, and orders that move part of those troops to another territory. What separates them is where you can play, what it costs, and whether the other side can be a person you know.

Prices change: check the store page before you buy. We do not print the price of games we do not publish.

1. Battle of Castles: the same move, with roads to defend

Battle of Castles is a real-time strategy game played in the browser at app.battleofcastles.com, and on Android through Google Play. You start with one castle. Point at a road and your castle sends half its garrison down it, every second, until you call the order off. Neutral castles are there to be taken, and each castle you hold produces troops and experience.

Where it leaves the State.io formula is the road itself. You can put a wall on a road to block it and stop arrows, a tower to cut down the troops that march into it, or a catapult to pound the castle across the way. Experience brings levels, and each level gives you a point to spend on a power, up to the super attack. Mana buys defences or one decisive blow. A 1v1 match lasts nine minutes, a 2v2 twelve. You win by taking every enemy castle, or by holding the most castles when time runs out.

For friends, the game has a code system: create a team, share the code, and either challenge each other one on one or team up for a 2v2. Our guide to playing with a friend walks through it.

Where others do better: Battle of Castles has no level-by-level campaign like State.io, and no big free-for-all.

2. Galcon 2: an older classic of the genre

Galcon 2: Galactic Conquest, by Hassey Enterprises, describes itself on Steam as "a demolition derby in space": you send swarms of ships from planet to planet to conquer the galaxy. It has been on Steam since December 2014, is free there, runs on Windows, Mac and Linux, and Steam lists it with multiplayer, co-op and cross-platform multiplayer.

Pick it if you want the purest version of the idea on a computer, with no castles and no building, just fleets and timing.

3. Mushroom Wars 2: a campaign and heroes

Mushroom Wars 2 is developed by Zillion Whales and published on Steam by Azur Games. Its Steam page promises "short but fierce RTS battles" between mushroom tribes, a hero to lead your army, several multiplayer modes and a story campaign. Steam lists single-player, online PvP and split-screen PvP. It is a paid game.

Pick it if you want a long solo campaign before, or instead of, playing online. Battle of Castles has none.

4. Auralux: Constellations: the minimalist one

Auralux: Constellations, by Grove Street Games and E McNeill, calls itself "Real-Time Strategy, deconstructed". You start with a single planet, then upgrade, expand and attack until the whole system is yours, with one new mechanic per constellation. It is paid, on Windows on Steam, and its page adds that you can play against friends "in local or online multiplayer games".

Pick it if you liked State.io for its calm puzzle side rather than for the fight, whether you play alone or against friends.

5. Territorial.io: many players on one map

Territorial.io, by Pixel Frontiers, plays in the browser at territorial.io and on Android. Its Google Play page describes "massive multiplayer conflicts" and "competitive one-vs-one duels" on historical and auto-generated maps, and states that the Android version contains ads.

Pick it if you want crowded maps more than a two-player duel.

What Battle of Castles does not do

• No offline play. Every match runs on our servers, so you need a connection.
• No level-by-level campaign. A guided tutorial teaches you the game, then you play matches.
• No App Store app. On Android there is the Google Play app; on a computer, the browser.
• A match takes nine minutes in 1v1 and twelve in 2v2: not a five-minute break.
• Landscape only on phones.
• 1v1 and 2v2 only, no large free-for-all like Territorial.io.
• No in-game chat. With a friend, use your usual call or messaging app.

Which game for your situation

You play on your phone on the bus and want quick solo levels: State.io itself, or a campaign game like Mushroom Wars 2, will suit you better than the online games on this list.

You want a long campaign with a story: Mushroom Wars 2.

You play on a computer and want the classic formula for free: Galcon 2.

You want to take on a crowd of players on the same map: Territorial.io.

You want to open a link and play right away, on a computer or an Android phone, and challenge a friend who is somewhere else: Battle of Castles.

FAQ

Can you play State.io online against a friend?

Its Google Play page speaks of a "free RTS online" and asks for a permanent internet connection, but files the game under "Single player" and mentions no way to challenge a friend (page read on 18 September 2026). To face a friend, choose a game with a friend mode: Battle of Castles (browser, Android), or Galcon 2, Mushroom Wars 2 or Auralux: Constellations (Steam).

Is there a game like State.io that runs in the browser without a download?

Yes. Battle of Castles and Territorial.io both run in a web browser. Battle of Castles also needs no account.

Are these games free?

Battle of Castles is free, with no ads on our site or in the Android app. Galcon 2 is free on Steam. Territorial.io is free, with ads in its Android version. Mushroom Wars 2 and Auralux: Constellations are paid on Steam.

Can I play a game like State.io with a friend on another device?

In Battle of Castles, yes: you each create a team, one challenges the other with its code, the other accepts. A phone and a computer can meet in the same match.

---

Sources, read on 18 September 2026: Google Play pages of State.io (io.state.fight) and Territorial.io (territorial.io); the territorial.io website; Steam pages of Galcon 2: Galactic Conquest (294160), Mushroom Wars 2 (457730) and Auralux: Constellations (444130). Store pages change: check them before you choose.