It was probably a mistake to follow Maria with another "big beast" like After the Flood. It didn't help that I did not do a great job of explaining the rules, and everyone's brains were a little fried by this stage, I suspect. And to be honest, After the Flood did not benefit from the comparison. After Maria it seemed - well - unpolished. A little bit fiddly, and lacking in drama perhaps.
I still rate this as a very good game indeed, probably an 8, but a game of this complexity and length needs to be the main event. Definitely not a wind-down game. (Chicago Express or Nexus Ops might have been a better choice.)