They either freeze, don't run at all or are multiplayer but lack a server list therefore can't be played. It's a shame because they look like they are fun.

Who is "your"? Itchio isn't a game studio. They are simply a platform that people release games on, like Steam, Humble Store, GOG, or Origin.

If you're having a problem with a game, contact the developer via their game's comments/forum, twitter, or email.