Add characters, stages, and music, then press Build & Play. Everything is saved right here in your browser — no account, no upload.
⚠ ONLINE PLAY — READ THIS FIRST
To play online, you and your opponent must be running the exact same game: the Build ID on the loading screen must match, which means identical characters and stages — anything added or removed here changes your build only, so your opponent has to make the same changes. Use the same Theme on both sides, and pick the same netcode. Connection quality depends on both players' networks — results may vary.
GAME MODE — WHAT EACH BUTTON DOES
Normal mode + online — loads the game exactly as shipped: your added characters, stages, music and theme are not loaded. Because nothing changes the build, every Normal-mode player shares the same Build ID, so you can match anyone online. Pick this for public matches, or when you haven't added anything.
Custom (mods) + online — loads everything you added (characters, stages, music, theme). Your Build ID then depends on your content, so online you will only match players running the exact same build — the game checks this and refuses a mismatch. Pick this to play with your mods, for example against a friend who made the same additions.
Tip: if a match fails to connect, both sides must pick the same mode and the same netcode.
To play online, you and your opponent must be running the exact same game: the Build ID on the loading screen must match, which means identical characters and stages — anything added or removed here changes your build only, so your opponent has to make the same changes. Use the same Theme on both sides, and pick the same netcode. Connection quality depends on both players' networks — results may vary.
GAME MODE — WHAT EACH BUTTON DOES
Normal mode + online — loads the game exactly as shipped: your added characters, stages, music and theme are not loaded. Because nothing changes the build, every Normal-mode player shares the same Build ID, so you can match anyone online. Pick this for public matches, or when you haven't added anything.
Custom (mods) + online — loads everything you added (characters, stages, music, theme). Your Build ID then depends on your content, so online you will only match players running the exact same build — the game checks this and refuses a mismatch. Pick this to play with your mods, for example against a friend who made the same additions.
Tip: if a match fails to connect, both sides must pick the same mode and the same netcode.
Characters
Drop a character folder or .zip
a folder/zip containing the character's
.def and its files
Stages
Drop a stage folder or .zip
a folder/zip containing the stage's
.def and its sprites
Music
Drop an .ogg or .mp3
use the dropdown on a stage to assign it
Theme
Drop a screenpack folder or .zip
a motif with a
system.def — changes the menus, select screen and lifebars
Loading screen art
Drop one or more image files (PNG / JPG / WebP)
decorative only — shown on the loading screen as a full-screen slideshow,
simultaneous side panels, or a small logo. Never affects the Build ID or netplay.
logo position
These mods live in this browser only — they aren't uploaded and won't appear
for other players. To share a build, use the downloadable Modding Kit (see the game's docs).