I am liking what I see there. I actually had a feeling that Extraction would make a good gametype for recreating Invasion because of how it worked (namely spawning objects in and out and progressing objectives), but didn't have the time or know-how at the time to test it out.
Nice work from petetheduck! I wonder if he's tested things such as the Defenders' ability to stop an extraction-in-progress. But he definitely just blew my work out of the water, yeah.