The Co-Op option in Wo Long requires players to set a password so that only their friends can join their online lobby. Next, players will be prompted to select a mission and, once up to two friends join the multiplayer Wo Long session, will load into the level together from the start.
Does Mysterium include online play ? There is an online mode included in Mysterium. Does Mysterium have a local multiplayer mode ? Mysterium has a "Pass & Play" mode, allowing you to play against other people on one device.