i wanted to rent a cloud server becuz i wanted to make game server for [Rimworld online city mod] but of course you guys dont have that on your list and would it be possible to rent a could server and host a game server with a game that is not on your game library
A cloudserver can be used to run any game you want. It is not limited to the games nitrado offers for the gameservers.
But PLEASE keep in mind, a cloudserver is nothing like a gameserver. Especially if you want to run a game on it which nitrado doesn't provide. You have to do everything on your own. Starting at securing the server all the way to installing and configuring the gameserver. If you screw up the first part of making your server secure, your cloudserver can end up in a bot-net.
PLEASE read / view tutorials before ordering and make sure you know what you are doing.