Some games allow you to specify the port you want to use for the game. If your game allows such an option you can set the game to use a port that you know isn't blocked by your college. Your college has blocked these ports for a reason, they don't want students sucking up all the bandwidth for games. This is a college network, I personally don't blame them for blocking these ports.
It is possible to bypass a firewall with ARP poisoning, but the details of such a procedure are beyond the rules of this forum. However if the college is running a software such as Arpwatch, they will have the advantage with this method.