In 8 air control is a key too. I've win at first try even though i didn't know how to capture buildings, so after long battle I just wiped out all of his units.
Great game, but levels too easy. I won most maps with first try.
supergiantsfan: in 10 map battle in water was lost immideately. But you can kill one of his warmachines at first turn - it's on bridge. I've concentrated army to break towers at top-left corner, and built aircrafts several aircrafts to overcome enemy' bombers. After getting air control win was easy - AI somewhy don't build aircrafts.
Got first three badges from a first try. AI isn't too clever. He discards most useful cards and go insane very fast. I still haven't tried challenges though.
Hellbender, there are two possible explanations:
first - when travelling you create another reality which will not interact with reality from where you came. So it will be two realities: you invent machine in R1, travel to past, prevented invention in R2.
Second explanation - universe is free of paradoxes, so system of quantum equations has only nonparadoxal
This game is great, but i don't think it needs badges. Otherwise it will not be endless -you will just fight till day N, kill M zombies in a row, gain L expo and then go drink coffee thinking that you win. But zombies are still there so it's wrong.
I've started game from another computer and where are my savefile (or at least my medals)??? It's very sad. I was sure they are stored in game account, not in cookies on local computer.