A rather disappointing game considering the system itself had potential, but is unfortunately woefully incomplete (apparently more content is coming out as DLC, but the base content as it is is barebones).
Initially the game possessed a intriguing system of unlocking new units through the completion of mini-achievements, allowing your cards to evolve into a more effective and specialised fighting force. Unfortunately this feature is only seen in the first half dozen cards before never being seen again.
The game also featured several factions with different tactics and units that you can mix and match. Unfortunately again, all the factions with the exception of the army (Union and Confederate's are both considered the same, begging the question as to why it is set in the Civil War) have barely enough cards for a playable deck, much less one that you can base a unique strategy out of. This is further made worse by every faction's units being essentially the same thing (Army riflemen and bandits have absolutely no distinguising characteristics between them).
Even worse, the potential dynamic was there, in the form of unattainable weapons and units the computer gets during the campaign. After completing the game, and every last achievement (both single player and multiplayer) I was upset that the only things I receieved were more of the same cards. Indeed, the final boss's deck is displayed as an available playable faction, but does not have a single unit or weapon card in it.
The story serves it's purpose I suppose, so it is hardly disappointing, but it is somewhat baffling that early in the story you can clearly see a sibling rivalry, only for one of the brothers to disapear, and only come back at the end of the game to do absolutely nothing, unlike the collection of minor characters who assemble for the purpose of serving as an Deus Ex Machina during a mission. Whoever is actually manning and directing your ironclads is never mentioned (unless it is assumed that the sergeant who gets a brief mention early in the game is the PC). The Civil war is barely mentioned, and the game might as well be set during the Anglo-Russian war for all it matters.
The campaign itself is not so much challenging as it is putting you in a situation with an outright disadvantage. In the early stages this disadvantage is negated by unlocking a new weapon. However, due to the fact that there are no decent unlocks in the later missions the game simply becomes a matter of chance. Hoping that the luck of the draw gets you exactly the unit you need, and that the computer does not use the obnoxiously overpowered ability that he is granted this mission on the turn it would hurt the most. The last mission in particular is guilty in that the enemy boss is not only invincible (unless you kill two heavily armoured units guarding an electric outlet, and procede to occupy both outlets with infantry that can be killed instantly by said boss) but possessing a repetoire of weapons far superior to what you can get, and heals completely should you fail to stop him from going to your side. The strategy towards defeating him involves praying to your chosen deity that the enemy AI will decide to lay waste to your ironclads, rather then stepping on your infantry, and will stand still for that brief moment where you miraculously achieve enough firepower to destroy him in one turn. God help you if you decide to go for the achievements.
All that said, the game has potential. If it simply had more content and diverse factions that would allow for actual tactical options.