Since the game server is up and running and not having any issues this must be an issue on your side.
The issue however can be a few different things, but what must be understood plainly that something between the internet connection to your computer is being blocked or not let through, and since you can browse internet normally it's more than likely it's FeralHeart itself as the program it is that is being blocked either by.
-Your antivirus
-Your windows firewall
-Your modem or router.
These things you need to check up on and make sure feralheart.exe(the game itself) is allowed through to the internet. Many cases have we had lousy anti-virus software like Norton and Mcafee blocking the game, and the user must either allow the program through, or remove the antivirus completely.
It can also be the windows firewall in some cases, and then the game must be added to the exception list both in and out in order to go on the internet and play.
It can also be the modem/router that has a built in firewall that blocks certain port ranges and in that case enabling uPnP(universal plug and play) it will open up the ports needed.
I cannot give exact instructions on how to do it here, so if you're going to try any of the above I'd advise you to tutorial videos on youtube since it exist for these common things. There's no other way to sort out your issue unless it's a temporary one caused by connection issues due to your ISP.