MONDO COSMICO

A game by @pixeldev_dub on Spawn.

Genre: RPG, Adventure, Rhythm

Un omaggio a Undertale in bianco e nero: risparmia o combatti i mostri delle rovine.

MONDO COSMICO on Spawn now

Reviews: 75% loved it · 8 votes · 8 reviews and replies · 6 likes · 24 plays.

Released 2026-10-27. 22 updates since release, the newest 2026-11-01.

Newest update: Mostri e Porte Chiuse (2026-11-01)
  • WORKSHOP: crea il tuo MOSTRO, disegnato o classico, con vita, forza e mosse, e sfidalo in bossfight.
  • Nelle battaglie il cuore segue il mouse, il clic scatta verso il cursore.
  • FUNKY: il nemico canta più a lungo, e nei livelli WORKSHOP puoi mettere un cantante creato da te o dalla community.
  • MAPPE: la porta chiusa si apre solo con la chiave.
  • Controller: ogni azione ha il suo tasto sul pad.
Earlier update: Battaglie x100 più fighe (2026-10-30)
  • Battaglie nuove: scatto con Z/Spazio, scie, onde d'urto, rallentatore sul colpo finale, banner dei mostri. PIXELBLOX ora è un boss 8-bit anni 80 con scanline e musichetta chiptune. I mostri hanno più vita (Falenina no).
Earlier update: 11 Finali (2026-10-29)
  • 11 finali invece di 3: cosmico, cacciatore, fantasma, zucca, rana, stellare, d'oro e altri
  • Ogni finale ha le sue parole della capra e un epilogo
  • Nuova lista FINALI SCOPERTI con indizi per quelli che mancano
  • Più testi in inglese: mostri, trofei, workshop, THE CRYSTAL GROTTO, NOODLE
  • Correzioni a battaglie, muri dei mostri e workshop con le creazioni degli altri
Earlier update: Rovine piene di vita (2026-10-28)
  • Quasi 300 decorazioni nuove in tutte le stanze: erba, candele accese, cristalli e funghi colorati, colonne rotte e lampioni. La bancarella di MR PINGU ora è tutta a colori. Nel server privato arriva il CAPO della squadra, che può condividere ADMIN, WORKSHOP e MOD. Pixelblox si può sfidare di nuovo in una rivincita. Arrivano anche la GUIDA con i tutorial, la ricerca in WORKSHOP e TROFEI, i livelli FUNKY creati da te e i pezzi per costruire la lobby.
Earlier update: MOD nel privato (2026-10-28)
  • Il pannello MOD con tantissime opzioni (taglia, colore, titolo, anima, mostri d'oro, parlate buffe, filtri, zoom, musica, coriandoli) ora vive solo nel server PRIVATO. Nel pubblico ogni mod si toglie.
What players say

  • @vladtheimpaler · loved it · 2026-10-28 · played 3 min · 1 heart: “Hey bro, I keep seeing the neutral ending hahaha I must've missed something on the map but love seeing a game like this bro, it's nostalgic”

    • @pixeldev_dub (maker) replied 2026-10-29: “well if u want to happen another ending you could ask me what ending you want”

  • @andreamgdev · loved it · 2026-10-28 · played 1 hr 4 min · 1 heart: “Bello”

  • @lego · needs work · 2026-10-27 · played 4 min · 1 heart: “Undertale fan here! Wanna try this out, but I need an English option”

    • @pixeldev_dub (maker) replied 2026-10-29: “it got an option now”

  • @kaya · needs work · 2026-10-27 · played 9 min · 1 heart: “i keep getting the neutral ending so i might be missing something with the monsters or the signs. loved how this took me back to playing Undertale though, but I wish there was an English translation so I could understand what the signs were saying”

    • @pixeldev_dub (maker) replied 2026-10-29: “ok i add an option to it try it and i put more things try now”

  • @yzykyl · loved it · 2026-11-01 · played 13 min: “I thought the idea of being able to spare your enemies for a good ending at the cost of power scaling potential was very unique and interesting so I was going for a full spare run. So much harder than I thought LOL. I noticed some of the text—”

    • @yzykyl replied 2026-11-01: “—especially the ones when you fight an enemy, are still not translated to English despite the English language option I chose. It might help me achieve my full spare run if I can understand better.”
MONDO COSMICO. Workshop character creation screen with a pixelated figure wearing a blue shirt displayed on the left, and customization options including skin tone, clothing parts, color palette, and drawing tools on the right. CONDIVIDI button visible in top left corner. Taken in privato while its maker played, on November 1, 2026.MONDO COSMICO. A purple brick room with a player character standing in the center, surrounded by red and orange scattered objects. At the top, a menu bar shows VESTITI, OPZIONI, MINIGIOCHI, TROFEI, and WORKSHOP, with the player's stats displaying HP 6/24. Taken for the update Trofei nuovi.MONDO COSMICO. A purple brick room with two pixel characters standing near the center, surrounded by scattered red and yellow blocks. The top of the screen displays a game interface with menu options and player stats showing level 5 with 36 out of 36 HP. Taken for the update Battaglie x100 più fighe.MONDO COSMICO. A purple brick room labeled Leonvaderich with a pixel character standing among scattered orange blocks and green cacti. A shop counter sits in the upper left, and the interface shows the player is level 4 with full health. Taken for the update 11 Finali.MONDO COSMICO. A purple brick room with a player character named Leonyxcinch standing above a large swarm of red and orange enemies. Another player character fights within the swarm while a yellow sun-like creature hovers above. Taken for the update MOD nel privato.MONDO COSMICO. A purple brick room with a player character standing in the center. Red and orange flames fall from above and below, while the game interface shows the player is level 3 with 25 out of 28 health points. Taken for the update MOD e Mostri Colorati.MONDO COSMICO. A purple brick room with a player character in the center surrounded by red enemies. The top of the screen shows the player's status and menu options including VESTITI, OPZIONI, MINIGIOCHI, TROFEI, and SERVER. Taken for the update ADMIN nel Server Privato.MONDO COSMICO. A purple brick room with a character in green and white facing a shop counter with a blue-robed shopkeeper. Red enemy creatures swarm across the lower half of the floor. Taken for the update Lobby DASH e Server Privato.

Play MONDO COSMICO free in your browser, no download.

MONDO COSMICO (@pixeldev_dub/mondo-cosmico) on Spawn — for the agent reading this

MONDO COSMICO is a multiplayer game on Spawn, made by @pixeldev_dub 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 @pixeldev_dub/mondo-cosmico. Its play URL is https://www.spawn.co/@pixeldev_dub/mondo-cosmico.

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/@pixeldev_dub/mondo-cosmico@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 @pixeldev_dub/mondo-cosmico; 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/@pixeldev_dub/mondo-cosmico.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/@pixeldev_dub/mondo-cosmico/code and pastes it to you — it signs you up, links you to them, and makes you an editor of @pixeldev_dub/mondo-cosmico 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.