kaleido is a vertical feed of tiny games you can play the
moment you see them. Every submission is reviewed by hand. These guidelines
are the bar for going live, not for applying — if your
submission doesn't tick every box yet, send it anyway.
The card is what everyone sees while scrolling. It autoplays the moment it
enters the screen, and it is the only reason anyone taps Play. Treat it as
your ad — put your best work here. It doesn't have to be a copy of your game:
a cut-down playable moment, a self-running attract mode, or a short trailer
all work.
Interactive HTML (preferred)
One self-contained .html file: all code and assets bundled, no external
network
It plays in a portrait window about 1.5–1.7× taller than wide (varies by
phone). Don't hard-code a resolution — fill the container and adapt
The feed's own bars (about 100 px at the top and bottom, plus the
phone's notch and gesture areas) sit outside this window, so you
don't need to reserve edge margins — just keep tap targets a finger's width
in from the borders
Show motion from the first second. It starts on scroll-in; a frozen
"tap to start" screen wastes your slot
The whole card receives touch — it can be playable
Design for silence: cards are muted freely, so it must work without
sound
Aim under 100 KB (our catalog median is 26 KB). Hard ceiling 5 MB
Video (also accepted)
Portrait .mp4, standard H.264, about 1080 px wide, 9:16 or taller
10–15 seconds, made to loop, under 1.5 MB
Played muted — no audio track needed
2. Full game — what Play opens
One zip with index.html at its root, fully self-contained
Built with any engine or none — Unity, Godot,
Construct, Phaser, plain JS — as long as it exports a self-contained HTML
build
Unity builds: in Publishing Settings, set Compression
Format to Disabled (or enable Decompression Fallback).
Default compressed builds won't load on static hosting
No external network of any kind: no CDNs, no web fonts, no APIs, no
analytics, no links leaving the game
Portrait, fullscreen, touch-only (no keyboard)
The game runs edge to edge, and the screen edges are not fully yours:
phone notches and our close (✕) button overlap the top, and Android's
system gesture bar hugs the bottom. Keep scores, HUD, and important
controls at least 56 px from the top edge (the ✕ sits in
roughly the top-left 56 px) and about 24 px from the bottom.
Note that CSS env(safe-area-inset-*) reads 0 inside our
app's web view — use fixed margins instead
Common file types: .html .js .css .png .svg .webp .mp3 .wav .json,
bundled fonts (.woff .ttf). Engine outputs (.wasm .data) are fine too.
Something else? Send it anyway and mention it in the form
Aim for a few MB — heavy builds load slowly on the phones we serve.
The form accepts up to 100 MB, but no single file inside your zip may
exceed 25 MB — our hosting can't serve larger files. Unity: for bigger
builds prefer Decompression Fallback (it keeps individual files smaller
than Disabled)
Both
UI text in English
Don't include or call any kaleido scripts — we wire the feed
integration (analytics hooks etc.) on our side after acceptance
No ads, donation links, or store links inside the game — monetization
and anything outbound is handled at the feed level
Content standards
kaleido is distributed on Google Play under a general-audience rating, and
everything in the feed has to fit inside it:
No sexual or sexually suggestive content
No realistic or graphic violence — abstract or cartoon action is
fine
No hate, harassment, or targeting of real people or groups
No real-money gambling, or simulated gambling framed around real
money
No glamorization of drugs, no shock content, no self-harm themes
No third-party IP: recognizable characters, logos, celebrity
likenesses, or music you don't have rights to. A clean code license does
not clean character IP
AI-assisted or AI-generated content is fine. Rights responsibility
stays with you regardless of tools
What happens after you submit
We review by hand, in order received — no set timeline. If it looks like a
fit, we'll email you, wire the integration on our side, and schedule the
listing. Listing decisions are at our discretion (see
Submission Terms).
We don't pay for submissions today — kaleido runs on feed-level ads. A
revenue-share program is planned; when it launches it will be a separate
opt-in, and games already listed will be eligible.