Glad you liked the game overall! Yeah, we wanted the discovery of the "compound" or "boosted" buildings to be a surprise, but we could have hinted in the tutorial that there could be hidden combinations :P Sadly we did the tutorial in a rush, like 20 mins before submission XD
We aimed for the kind of difficulty that make people fail on first try but win on second try (and then improve their scores on further tries), which seems to be your case and the case of many others, so I'm happy!
That's quite a high score! You probably managed to save everyone in your population :D Good job!