I love this game:
Basically, it's an RTS with time travel as a gameplay mechanic.
-> You can change the past to alter the outcome of a battle, or to retroactively prevent it from happening.
-> You can send the survivors of a battle into the past to help out their past selves.
-> You can distract your enemy or do some scouting with troops that soon will never have existed once the timeline corrects itself.
-> "Poor timeline management" can be a cause of death.
These are all things that mean something in this game. I recommend it; be forewarned that it will strain your brain.