An idea in.
A playable game out.
The AnnoMotion HTML5 Game Prototype creator turns a couple of lines of brief into a complete, self-contained game you can play in your browser straight away — arcade, puzzle, platformer, endless runner or shooter. Everything lives in one HTML file: no engine, no build step, no dependencies. Play it here, then download the file to run or edit anywhere. Powered by AnnoMotion AI.
See it in action
Watch a real run.
A written brief becomes an 8.4 KB single-file HTML game where a fox catches falling fireflies in a lantern.
What's inside
A working prototype, not a code snippet.
Getting an idea to the point where you can actually play it is the slowest part of prototyping — a loop, input handling, a score, a win state, a restart. The prototype creator writes all of it and hands you something you can play in the page, so you find out whether the idea is fun before you commit a weekend to it.
Actually playable
Every build is required to ship a real game loop, keyboard and pointer controls, a visible score or goal and a win/lose restart — not a fragment you have to finish yourself.
One self-contained file
Markup, styling and logic are inlined into a single HTML document with no libraries, CDNs or build tooling. Open it anywhere and it runs — including offline.
Play it in the browser
Your prototype appears right in the page, ready to play the moment it finishes. Go fullscreen to test it properly without leaving the tool.
Five genres
Pick arcade, puzzle, platformer, endless runner or shooter and the brief is interpreted for that shape of game, so the mechanics match what you asked for.
Yours to download
Download the .html and it's yours — host it, share it, or open it in your editor and keep building. Plain, dependency-free code you can actually work with.
Sandboxed preview
Previews run in a sandboxed frame denied same-origin access, so a prototype can only ever touch its own canvas — try anything without worrying about what the code might reach.
How it works
Pick a genre, brief it, play it.
Pick a genre
Arcade, puzzle, platformer, endless runner or shooter. The genre steers the mechanics the prototype is built around.
Describe the game
A line or two is enough — the goal, the twist, the feel. Name the mechanic you want tested and it gets built around that.
Play it, then take it
Play it in the page, go fullscreen, or generate another take. When you like one, download the single HTML file and keep going.
Built for
Jams, pitches and "is this idea fun?"
For the moment when an idea is still cheap to test, and building it by hand would cost more than finding out whether it's worth building.
Test a mechanic
Get a playable version of the idea in your head without building it, so you can feel whether it works before writing a line of production code.
Start a game jam
Skip the boilerplate hours at the start of a jam and begin from something that already runs, then spend the weekend making it good.
Pitch with a playable
Send a link or a file instead of a slide. A prototype somebody can play for thirty seconds explains an idea better than any deck.
Placeholder minigames
Fill an arcade cabinet, a side activity or a loading-screen distraction with something real while the final version is still on the backlog.
Learn by reading
Every build is plain, dependency-free code — a compact worked example of a game loop, input handling and win/lose state you can read end to end.
A starting point
Treat the download as scaffolding: keep the loop, replace the art, rework the rules, and grow it into the thing you actually wanted.
FAQ
Game prototypes, answered.
Is the result actually playable, or just a code snippet?
Playable. Every build is required to ship a real game loop, keyboard and pointer or touch controls, a visible score or goal, a win/lose or restart state and on-screen instructions. If a generation comes back as prose, or as a document that got cut off partway, it is treated as a failure and refunded rather than handed to you as a broken file.
What exactly do I get to download?
A single .html file. The markup, the styling and all the game logic are inlined into one document with no frameworks, no libraries, no CDN links and no build step, so you can open it straight from your desktop — including with no internet connection — or drop it on any static host and share the link.
Is it safe to run a game the AI wrote?
The preview runs inside a sandboxed frame that is denied same-origin access, so a prototype has no route to this page, your account or your browser storage and can only ever draw inside its own box — that is the real protection, and it holds whatever the generated code tries. On top of it, the generator is instructed not to use network requests, external files, cookies or local storage, and the download is served as a file attachment rather than executed by the site.
Which kinds of game can it build?
Five genres: arcade, puzzle, platformer, endless runner and shooter. The genre you choose is part of how the brief is interpreted, so the same description produces a different shape of game depending on which one you pick — worth trying more than one when you are still deciding what the idea is.
Can I keep building on it afterwards?
It is your file. The whole game is plain vanilla JavaScript in one readable document, so there is no project to configure and nothing to install before you can open it in an editor and change a rule, retune a number or swap out the art.
How much detail should the brief have?
A line or two, up to 1,500 characters. Naming the goal, the twist and the one mechanic you want tested works better than a long spec: the generator is explicitly told to prefer a finished simple game over an ambitious unfinished one, so a tight brief tends to come back more playable.
Make something playable today.
Pick a genre, describe the game, and get a self-contained HTML5 build you can play in the browser and download — powered by AnnoMotion AI.