This service is for verifying product ownership by IsoMetro users across storefronts (itch.io, Steam).
In line with Stop Killing Games, even the Free Edition of IsoMetro supports multiplayer sessions.
However, in order to make use of our additional convenience features (storing and distributing server listings, and assisting in hole punching so you don't need to set up port forwarding on a server in order to host), we require you to purchase the Gold Edition.