To beat hard mode easily, get Trojan Horse, after that all you need is resource cards, and double damage card(sometimes useful), then restart untill you start with a trojan. Then get resources, if you cant then discard and play it as you can. I won all battles in most 3 tries.
Awesome game, until the last level, where every mistake is made which was avoided in the previous levels, like lack of checkpoints which leads to frustration and too many repetition of a part. Obstacle where you need luck instead of skill, and parts where you die a lot in short time you can't see where did you make a mistake because of white flashing of the screen upon death. I wanted to give 5/5 but after this last level i didn't feel satisfaction, but relief that it's over. :(
worst decision game :(, i like the series beat all games before with no problems, but in this one i got black screen after every 4-5th game, awful system with the lack of engineers and soldiers... Unbalanced things like factories. First decision game that a i dont play trough. Very disappointing.