Cosmo Color: paint rockets, planets and robots with a little alien astronaut.
Cosmo Color is a cozy coloring game template for HTML5 with full source code, made for kids from 3 years old. It is set in friendly outer space, where a little green alien astronaut cheers every stroke: tap an area and the paint pours in like a little wave, with a happy note and a burst of sparkles. Nothing can go wrong: there is no score, no timer and no error sound, and every action can be undone. The game itself is only icons and pictures, so children can play before they learn to read.
64 pages in 8 themes
Space, Rockets, Planets, Aliens, Robots, Space Pets, Stars and Moon Base, eight pages each, with big, closed areas sized for small fingers. The drawing sits on a spaceship screen, and every finished picture goes to the gallery in a spaceship cabin, where it gets a medal.
Bucket, brush, stickers and stamps
The paint bucket pours color from the spot you tap, with a soft wave, a note from a gentle pentatonic scale and sparkles that grow with the size of the area. The stay-in-line brush never spills over the outline when a stroke starts inside an area. There are 16 stickers, 8 stamps in the chosen color, an eraser and an undo button (10 steps, even after "clear all"), plus 30 colors including skin tones and 4 special paints: glitter, rainbow, pastel and polka dots.
Zoom, saving and a little celebration
Pinch to zoom and drag on phones and tablets, or use the mouse wheel on desktop; drawing never happens by accident while zooming. Work is saved automatically in the browser. The "I'm done!" celebration comes in three beats (impact, a short pause, then stars, confetti and music) and can be skipped with one tap. The alien astronaut reacts to everything with 8 poses and falls asleep if nobody plays for a while. Pictures can be saved as a PNG, shared on phones and downloaded on desktop, with the file name in the player's language.
Settings in 14 languages
The Settings panel comes in 14 languages (English, Portuguese, Spanish, French, German, Italian, Dutch, Polish, Turkish, Russian, Japanese, Korean, Chinese and Indonesian), with separate sound and music volumes, vibration on supported phones and a reduced-motion mode that follows the system setting. Recorded background music fades out when nobody is playing.
Your game, your hosting
Upload the contents of the game folder to static HTTP(S) hosting. No PHP, database, account or Node.js is needed on the server. It works with touch and mouse, in portrait and landscape, on phones, tablets and desktop. There is no account, server, ranking, ads or payments, and nothing leaves the browser.
What this edition does not include
Native apps, hosting and custom development are not included, nor are accounts, server features, an online ranking, real-money purchases or an advertising SDK.
Who this template is for
Site and portal owners who want a gentle game for young children and families, schools and educational sites, freelancers and studios building a branded coloring game for a client, and developers who want readable plain JavaScript to learn from or reskin.
Customise it
All "game feel" numbers (wave speed, sparkles, zoom, celebration timing) live in one file, src/feel.js. Themes and coloring pages are listed in one place, so you can add, remove or reorder pages, and a new page is plain PNG line art: the game finds the paintable areas by itself. Tests run with npm test, npm run build copies the game to dist/ and npm run serve starts a local server.
Technical details at a glance
- Stack: HTML5, plain JavaScript ES modules (no compile step), Canvas 2D and Web Audio.
- Saves settings in localStorage and pictures in IndexedDB, in the player's own browser.
- Settings in 14 languages; offline illustrated guide in English, Portuguese and Spanish, plus a customization guide.
- Node.js 26.13+ only for the optional tools: tests, build copy and local server.
- No third-party code in the game: system fonts and no libraries.
