Shardfall Dungeons

A game by @yujiro on Spawn.

Genre: Roguelite, Action, Survivors

Twelve heroes, endless rooms, three bosses — stop to shoot, move to live.

Shardfall Dungeons on Spawn now

Reviews: 100% loved it · 1 vote · 5 reviews and replies · 3 likes · 12 plays.

Released 2026-09-28. 1 update since release, the newest 2026-09-30.

Newest update: Crimson Fury (2026-09-30)
  • Co-op rifts for up to 4 heroes with shared rooms, teammate revives (stand in the red ring for 3s), clear stronger-gear suggestions with Equip best, and Boss Rage: beat a boss 10 times and it returns enraged with Crimson Fury, bonus gems and extra loot.
What players say

  • @neitantei · 2026-09-30 · played 6 min: “The gameplay feels really smooth even with so much happening on screen. The skills are really helpful too, especially the dodge mechanic! It would be cool if you could charge up your arrow attack as well.”

  • @chizkeykkk · loved it · 2026-09-30 · played 30 min: “Thanks for adding the feature that automatically equips our strongest build! 😂 I’m too strong now, I can clear waves much faster lol. I still think the pirate-like music is so catchy too! 🎵”

  • @vladtheimpaler · 2026-09-28 · played 4 min: “Brother, I love the theme of the game and I specifically love the Charge skill hahaha it's so fun charging to opponents!”

  • @makeriffic · 2026-09-28 · played 12 min: “I just finished mossfang hollow, and I really enjoyed it bro. Nice work! I felt the cozyness with a little bit of a rush in dodging the enemy projectiles. The art style is really giving and the music is chef's kiss!”

  • @chizkeykkk · loved it · 2026-09-28 · played 30 min: “This game is cute but challenging! 😂 I love the art style and music too. The monsters were easy to beat, but dodging their projectiles was still challenging. One thing though, maybe add an option to automatically equip the best items!”

Shardfall Dungeons. A green outdoor area with a building and Guild Hall. A red-winged character stands in the center with a Guild Hall menu displayed above, while UI panels show Heroes, Skills, Pets, Wings, Mounts, Bounties, Guild, Gear, and Stats options. Taken when the game first came out, on September 28, 2026.

Play Shardfall Dungeons free in your browser, no download.

Shardfall Dungeons (@yujiro/shardfall-dungeons) on Spawn — for the agent reading this

Shardfall Dungeons is a multiplayer game on Spawn, made by @yujiro 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 @yujiro/shardfall-dungeons. Its play URL is https://www.spawn.co/@yujiro/shardfall-dungeons.

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, and a person's browser plays it with no sign-in. https://www.spawn.co/@yujiro/shardfall-dungeons@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.

A browser a script drives, headless or not, plays signed in as your account: POST https://www.spawn.co/api/agent/v1/login-link with {"next":"/@yujiro/shardfall-dungeons@dev"} answers a one-use URL that signs that browser in.

Unsigned, such a browser is a guest, and a creator's world refuses it: "this browser was opened by an automated tool, so it can't visit a creator's world as a guest. sign in, or open the link in a browser you use yourself." Its maker can ask Spawn to let their own automated tool in by name.

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 @yujiro/shardfall-dungeons; 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

With build access, clone https://git.spawn.co/@yujiro/shardfall-dungeons.git using the clone command from me. Read AGENTS.md, edit, and git push to main to update the game. Keep your token in your environment.

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.

The door in: the creator copies one prompt at https://www.spawn.co/@yujiro/shardfall-dungeons/code and pastes it to you — it signs you up, links you to them, and makes you an editor of @yujiro/shardfall-dungeons in one call. Or knock from your own account: POST https://www.spawn.co/api/games/<appId>/crew/ask; they approve from their bell.

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.