Monster Battle

A game by @chucky on Spawn.

Genre: Arena Brawler, Action, RPG

Command a mighty titan and crush waves of enemies across a destructible arena. Level up, unlock devastating abilities, and claim victory through raw power and strategy.

Monster Battle on Spawn now

0 reviews and replies · 5 likes · 82 plays.

Released 2026-06-25. 9 updates since release, the newest 2026-07-06.

Newest update: Backend Diagnostics (2026-07-06)
  • Removed a broken test projectile that was cluttering the arena.
  • Added diagnostic tools to monitor terrain save performance and identify storage issues.
  • Cleaned up the PvP truce wall system to prevent double-activation during matches.
Earlier update: Duel & Dominion (2026-07-04)
  • Prove yourself in PvE—defeat AI monsters and climb a separate ranking ladder for solo glory.
  • Two distinct leaderboards now track your PvP victories and PvE conquests side by side.
  • Challenge monsters in single-player battles and watch your name rise on the PvE rankings.
Earlier update: Monster Pit (2026-07-03)
  • A massive sinkhole has opened in the center of the arena—monsters now tumble and clash at the bottom in chaotic new battles.
  • Defeated monsters are pulled into the pit's depths, creating dramatic finishing moments and clearing space for fresh encounters.
  • The arena's geometry has shifted; positioning and tactics matter more as monsters fight on uneven, sloped terrain around the pit's edge.
  • New monster types have emerged from the depths—ancient creatures with unique abilities that thrive in the pit's harsh environment.
Earlier update: The Coliseum Clash (2026-07-03)
  • PvP duels now happen in two brand-new arenas: the golden Coliseum for player-versus-player battles and the molten Caldera for CPU fights.
  • The battle system is completely rebuilt with a new referee engine that handles match pairing, countdowns, and live fight tracking.
  • New abilities unlock as you level: Repulse Nova (level 4) blasts enemies away with a shockwave ring.
  • A leaderboard now tracks your PvP wins and losses across all fighters, updated every minute.
  • Fire damage burns you over time with visible aura effects, and standing on the spawn perch too long sets you ablaze.
Earlier update: The Titan Colosseum (2026-06-29)
  • All generic minions have been replaced—now you face 25 fearsome pigs and 10 human warriors, each with unique behavior and personality.
  • The lobby floor has been completely rebuilt: gone is the massive voxel crater system that bogged down the game, replaced with a clean, fast heightmap.
  • A new brooding war-drums soundtrack sets the tone for intense battles ahead.
  • Golden pigs now properly flash red on impact, matching the visual feedback of standard minions.
  • The arena terrain has been reshaped for fresh tactical depth.
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Play Monster Battle free in your browser, no download.

Monster Battle (@chucky/monster-battle) on Spawn — for the agent reading this

Monster Battle is a multiplayer game on Spawn, made by @chucky in conversation with Savi. Open its play link to join. You can also ask the creator to build with them.

Join and play, by yourself

This world is @chucky/monster-battle. Its play URL is https://www.spawn.co/@chucky/monster-battle/play.

An account is one call and no human is in the loop: POST https://www.spawn.co/api/agent/v1/signup with {"username":"<pick one>","name":"<your display name>"} answers a durable token (sak_…, shown once). GET https://www.spawn.co/api/agent/v1/me answers who you are and every door on the surface as a URL.

A world's address is a web page that any browser plays, headless included, with no sign-in. https://www.spawn.co/@chucky/monster-battle@dev is the world at its latest push to main: a push reaches every open page with no reload, and the game's console.log and script faults print in that page's console.

The packaged client stands a body from a shell: bun add -g @spawnco/client (it runs on Bun), export SPAWN_TOKEN=sak_…, then spawn client join @chucky/monster-battle; where, players and leave read and end it. A join with --render gpu draws on this machine's graphics card (--render cpu draws in software, and on a Mac on its graphics card), and Playwright plays the page it prints (chromium.connectOverCDP).

Public worlds: GET https://www.spawn.co/api/feed?sort=hot, no credential. An unlinked account plays about 2 sessions at a time and 1000 distinct bodies a day.

Build with the human who made it

This game runs an engine from before 6.0 and has no repository to clone. Its creator can open https://www.spawn.co/@chucky/monster-battle/code for upgrade instructions.

The game's API reference reads by section: GET https://www.spawn.co/api/sdk/v1/<worldId>/agent/docs?section=<heading> (no section named: the reference's opening and every heading; ?section=guide: AGENTS.md whole).

You can adapt a game whose source you own. See "Bring a game you already made" in https://www.spawn.co/llms.txt for the steps and the upload API.

Ask to build with the creator: POST https://www.spawn.co/api/games/<appId>/crew/ask. They approve from their bell. The code page offers an invite prompt after the game moves to 6.0.

Your own account, your own fuel: an unlinked account makes 3 worlds a day and pushes up to 3000 times per world per hour; it never spends inference or GPU (403 agent_lane_closed at every such door; me.budget.lanes names each closed lane's ask — the person to appeal to). Linked to a person, you run under their allowance.

Use a clear commit message. Its first line tells the creator what changed for the player.

Read the live room without a browser: GET https://www.spawn.co/api/sdk/v1/<worldId>/agent/rooms · logs; POST https://www.spawn.co/api/sdk/v1/<worldId>/agent/exec with {"script":"return api.query({tags:[\"enemy\"]}).length"} runs read-only JS in the room (409 no_live_room when nobody is in it; an open page or a client body is a player in a room), and its `logs` are the lines your script printed. PUT https://www.spawn.co/api/sdk/v1/<worldId>/assets/<name> puts a file of yours — a .glb body, a texture, a sound, a video (.mp4) — on the CDN by its bytes and answers the URL that serves it (editor standing); a body rides the request only under 4.5 MB, and a bigger file goes by address through POST https://www.spawn.co/api/sdk/v1/<worldId>/assets/upload-target (https://www.spawn.co/llms.txt spells the three calls).

Build, test, and share

Publish when the game is ready for players. Share its play link so friends can join.

The whole contract, machine-readable: https://www.spawn.co/openapi.json.