Thanks for playing and for the feedback :)
I'll look into that music volume change! I was thinking of making the volume slightly lower during transitions but I haven't gotten around to it yet.
I've gotten a lot of feedback regarding Observatory and I will definitely change it. I'm thinking of giving players ways to upgrade buildings and for Observatory, it would allow to generate knowledge automatically by hiring units and would also give new, powerful upgrades.
As for knowing which unit impacts booms generation the most - yeah, it's a good idea to add some sort of a chart for it although I don't quite know how to implement it. Might be tricky because Wizards impact Booms generation indirectly thanks to Barrage. Maybe Barrage could be counted as a separate source of booms generation though.