This game will either be friggen awesome, or crash and burn. I like the idea, and seems like it could really mind rape you. I didn't get the "build a unit in the future so it'll be in the present" at first, but I wrapped my brain around it and understood.
It'd be kinda weird though when you destroy something in the past. What if by destroying a unit training camp in the past, you are unable to build in the future to prevent an attack from the present. Let's say the other enemy teleported to the past during the present's attack. Would all your units in the present built by that unit factory suddenly dissapear or something?
...I....sdfsafasdfads mindFFFF. I still like the idea though.