What has Port done apart from BBB that is of interest?
He made (and cancelled) a Minecraft-to-Blockland conversion, Lots of little useful add-ons, He made some space marines versus star trek zombie thingies I forgot the names of, and currently he's working on a brand new zombie gamemode which FINALLY will work EXACTLY like L4D2. Oh, also, it already has support for custom zombies and addition scripts, I think it would be easy to make zombie defence with currency from it.