Pick a level, bring your friends, first clear wins. Progress syncs live from the DashStats mod.
A battle takes up to 8 players, and you can be in up to 5 battles at once, one per level. The host can set a time limit from 1 hour to 3 months; if it runs out, the highest percent wins. Only progress made after the battle starts counts. Wins, losses and past battles show on your profile.