My game says cannot reach the server

Is the port that your game client uses open through your server firewall?

-- sw

I believe so.

It could be that the game's using a different port than expected, or there could be a block in your Linode's firewall.

You can check which ports services are using on your Linode with:

netstat -pltnu

You can list all firewall rules in iptables with:

iptables -L -nv --line-numbers

If it's neither of those things, check to see whether your local computer's firewall is blocking the outbound connection or port.