You played the campaign and were unhappy, you couldn't play the SEAS? No problem with the SEASMOD. :) Just install it and you can play the SEAS on some maps, for example on Coldblooded. It includes a mappack with 5 community-maps. To play it, you need ParaWorld with the boosterpack, for multiplayer, all players have to install it. It's a mod, so you can easy switch between the normal PW and the SEASMOD-PW with 2 different shortcuts. ;) Get it now by clicking on "mods" or on this link.
Edit: There is also a mappack! Download it for more nice custom usermaps ;)