if you need help with DG2 Architect feel free to send me a friend request. It makes it a lot easier to chat, exchange files and generally get any problems sorted out more quickly.

Defense Grid 2 custom map releases in rough chronological order:
http://www.dg2freemaps.com/map-alienwarespacebase-by-grimlar/
http://www.dg2freemaps.com/map-flower-v2-by-grimlar/
http://www.dg2freemaps.com/map-cubical-moments-part-1-by-grimlar/
http://www.dg2freemaps.com/map-ss-space-butterfly-by-grimlar/
http://www.dg2freemaps.com/map-helical-dn8-3-by-grimlar/
http://www.dg2freemaps.com/map-festive-tree-by-grimlar-2/
http://www.dg2freemaps.com/map-festive-pudding-by-grimlar/
http://www.dg2freemaps.com/map-cubical-moments-part-2-by-grimlar/
http://www.dg2freemaps.com/map-quad-by-grimlar/
http://www.dg2freemaps.com/map-festive-turkey-by-grimlar/
http://www.dg2freemaps.com/map-festive-greetings-by-grimlar/
http://www.dg2freemaps.com/map-two-teslas-by-grimlar/
http://www.dg2freemaps.com/map-corkscrew-bridge-by-grimlar/
http://www.dg2freemaps.com/map-cloud-base-alpha-by-grimlar/
http://www.dg2freemaps.com/map-qad1-by-grimlar/
http://www.dg2freemaps.com/map-qad2-by-grimlar/
http://www.dg2freemaps.com/map-qad4-by-grimlar/
http://www.dg2freemaps.com/map-qad3-by-grimlar/
http://www.dg2freemaps.com/map-toxi-city-by-grimlar/
http://www.dg2freemaps.com/map-festive-snowman-by-grimlar/
http://www.dg2freemaps.com/map-festive-pumpkin-by-grimlar/
http://www.dg2freemaps.com/map-arrti-by-grimlar/
http://www.dg2freemaps.com/map-cubical-moments-part-3-by-grimlar/
http://www.dg2freemaps.com/map-cnsq-by-grimlar/
There may be more...