There's no block in place to restrict anyone from playing City of Villains/Heroes or any other game for that matter. Unfortunately these particular games require that local ports (2104,2106,6994,7000-7100) be available on the client PC (your computer) and directly reachable by their servers. Due to the design of our network, this is impossible without tediously setting up specific exceptions for each user.
I'm not sure how to explain without getting a little technical. We use private non-routable IP addresses on campus for a number of justifiable reasons, and when you access the internet each connection attempt is translated over to a external routable IP. When the game server attempts to establish a direct connection back to your computer, it's unable to do so because your actual local IP is non-routable and you have no permanent external address.
Most online games don't work like this, since so many users are using home routers and NAT (network address translation). I'm honestly a bit surprised that a modern game would require open ports to be available on the client PC in order for the game to work. In most other games, a persistent connection is established from the client to the server.