Vibe coding a game: what works, step by step

Andrej Karpathy coined “vibe coding” in a February 2025 post on X, describing a style where you “fully give in to the vibes” (the post). Collins named it its Word of the Year for 2025 (Collins).

Vibe Jam 2026 turned the term into a rule, and its entries make up 367 of the 403 games we list as of September 30, 2026.

What did Vibe Jam 2026 require?

It required AI-written code, new games and free play on the web, over one month from April 1 to May 1, 2026 (jam rules).

• AI share: at least 90% of the code written by AI.
• New work: no games that existed before April 1, and one entry per person.
• Access: playable on the web, free, with no login or signup, and loading almost instantly, without loading screens or heavy downloads.
• Widget: the jam’s JavaScript snippet in the game, or the entry was disqualified.
• Entries: 945 games, according to the jam’s press page.

The rule counts who wrote the code. Karpathy’s post was about forgetting the code exists, and the jam asks nothing of the kind.

Vibe coding game jam compares these rules with what other jams allow.

What do vibe-coded games look like?

In our catalog, 66% run on Three.js, 64% list mobile and 43% have online multiplayer.

Data note: as of September 30, 2026 the catalog lists 403 games, 367 of them Vibe Jam 2026 entries (jam rules: at least 90% of the code written by AI). Creators name the tools themselves, mostly in the jam submission form. We don’t verify them.

Trait	Games (of 403)
Built on Three.js	265 (66%)
List mobile as a platform	256 (64%)
Have online multiplayer	173 (43%)
Name Claude Code	169 (42%)
Name Codex	72 (18%)
Name Cursor	86 (21%)

Action is the most common genre tag, on 176 games. Shooter (93), simulation (67) and strategy (65) are also common. A game can carry up to three genres, so the counts overlap. Browse the action, shooter, simulation and strategy hubs to see them.

Our reading: a listed vibe-coded game is usually a real-time scene in a browser, often playable on a phone and often with other players. Weigh the jam’s own nudges, though. Its rules say Three.js is usually recommended and multiplayer games are preferred but not required.

Not every game follows the pattern. HALDANE-4, a horror descent under the Antarctic ice drawn in ASCII and made with Cursor, lists no engine; it placed fifth and won Most Original. 74 of the 403 name no engine.

Which habits keep a vibe-coded game playable?

Small loops keep a game playable while it grows. For scale, Kanso, a bonsai game that placed ninth and won the jam’s Most Zen award, was built in about a week with Codex, according to its creator.

1. Describe one loop in one sentence. Catalog taglines show the scale. Fanto’s Mega-Mart, second at Vibe Jam 2026, is a race “through a haunted grocery store at rocket speed, grabbing items as you go.”
2. Ask for the smallest playable slice. Movement, one hazard and a score. Run it before you ask for more.
3. Play after every change, then report what you saw. Claude Code’s docs advise giving the agent the symptom, the likely location and what “fixed” looks like (best practices). The table in the next section shows the difference.
4. Write the standing rules down once. The engine, the run command and “play a round after every change” go in CLAUDE.md or AGENTS.md, which the agent reads every session. 10 prompts to copy has a four-line example.
5. Commit every version that plays. git add -A && git commit -m "wave spawner works" takes seconds, and git restore . throws away uncommitted edits to tracked files when an attempt goes wrong. Claude Code’s checkpoints are not a replacement for git, according to its docs.
6. Restart when the session gets messy. After two failed corrections, the same docs advise clearing the session (/clear in Claude Code) and writing a sharper prompt.
7. Polish last, one effect at a time. Once the loop is fun, screen shake, a hit sound and a death animation each get their own message. Game feel with AI has the numbers to start from.

Which prompts work better?

A specific prompt names a symptom, a place and what fixed looks like. The pattern comes from Claude Code’s docs; the examples are ours.

Vague	Specific
Make the game more fun.	Enemies spawn every 10 seconds. Add a wave counter and add two enemies to each new wave.
Fix the controls.	On a phone, dragging the left half of the screen moves the ship and tapping the right half fires. Right now dragging scrolls the page.
It runs slowly.	On my phone the frame rate drops to about 20 when 50 enemies are on screen. Find the cause, fix it and tell me what you changed.

A first prompt in that spirit:

Build a one-page browser game with Three.js. The player flies a small ship: drag to move, tap to fire. Enemies drift in from the top and the run ends when one touches the ship. Show the score. Run it and tell me what you see.

For a template at each step of a build, see 10 prompts to copy and adapt.

Where does vibe coding a game go wrong?

Mostly in code nobody checked, scope that grew too early and rules nobody read.

• Code nobody checked. Claude Code’s docs warn about plausible-looking code that misses edge cases, and tell you not to ship what you can’t verify. Playtesting games with AI turns that advice into a test the agent runs itself.
• Scope that grew too early. Multiplayer adds a server, netcode and hosting. Add it after the single-player loop is fun, and read make a multiplayer game with AI first.
• Rules nobody read. Vibe Jam 2026 required AI-written code, while other jams and stores set their own terms. Selling AI-made games covers Steam and itch.io.

On Steam, the public documentation names art, sound, narrative and localization as the content to disclose (Content Survey). Game Developer reported on January 16, 2026 that code helper tools used for workflow do not need disclosure (Game Developer).

Next: pick a tool and ship

Start with how to make a game with AI for tools and publishing. See what each agent produced on the Claude Code, Codex and Cursor hubs, or compare them in best AI game makers. For a jam, read vibe coding game jam.

Browse the Three.js hub, the Vibe Jam 2026 entries and the top rated games. Made one yourself? Submit your game.