Unlike others I like it better than band of heroes! :)
It has more levels, has a steeper difficulty (band of heroes felt too easy) and the meta-game of training up multiple parties is very nice! That is what makes this game replayable, while band of heroes is over much faster.
The best party imho has a thief leader (for the fast shooting ability, the arrows part of the power ability does not even matter compared to that awesome fast shooting!) with two ninjas on the side, all with 5 shooting of course.
A few things that could be improved are:
*) add NG medals
*) obtain items as drops in levels rather than chests and "premium currencies"
*) it's annoying that there is a mission to upgrade weapons because that makes you want to wait with upgrading weapons til there are such missions
*) scrolling of your heroes in items panel is supper slow
*) the missions "no equipment" are annoying because removing/adding equipment is so tedious
*) the quests could be taken further, requiring you to raise more parties to level 15
*) the wizard classes are very bad compared to the other classes. Their lightning should not have a distance limit, make wizards useful in parties with other classes by giving them the same range (infinite). Not only is it limited range but it shoots at such low rate that whenever you're close to someone the wizard happens to not shoot anyway, and by then the monster is long dead by a much more awesome ninja. The wizard special abilities suck. Just look at their ability, and the much more awesome abilities of the thief (faster shooting for everyone) and druids (5 of those wolves/snakes is amazing, and permaheal for everyone). Wizards ability? a lame shot, move a bit faster or heal only self not even whole party...