Really great concept, but I find it too complex for such a short experience. For instance, I would expect that repairing and delaying impacts require only to get a correct unit on a tile without spending commands on action, taking into account how difficult it is to get anywhere in time. Also different terrains does not make it more fun. The main issue is that you cannot actually plan anything up front, you can just react on what's coming, and if your engineers or military are too far, well, you cannot do anything. Surely it contributes to the narrative, but for such a complex game having so little control feels frustraiting.
I see two ways how to impove this: 1) make it less complex; 2) give player more turns before an impact to prepare which would make planning possible.
Anyway, very good entry and very impressive for a jam in terms of polish and quality. Good job!