There's a bug in the money/XP posting that truncates zeros between the period & the next non-zero value.
The store selection is random, why not give us a full selection rather than make us re-click frantically, lvl 2 gear is too high priced to compare to buying extra soldiers at first, the selection never seems to upgrade, the drawings of the different lvl armours are too similar to distinguish.
But the big flaws are in the knowing: you can't know gear improvements before buying (specially since the same gear gives different bonuses at different character lvls) You can't know if the char glowing effect is a crit hit or some sort of healing notice, with duplicates of every char you can't know which one is dying faster, supposing you equip/lvl them differently to try to compare & understand game dynamics. You can't even know if your goal is to traverse a screen or if it's better to simply restart each screen at first death, or how fast you damage different monsters. Your character's tend to bunch up so your own health bars are unreadable.
The character movement algorithm is retarded, and always leaves your archers vulnerable. The fact that skelly archers are tougher than skelly macemen is counter to all sense, so forget trying to understand the new monsters until the become trivial to kill. The ads pop up in a jarring and annoying way (warn a fellow with a short lead in, it looks like flash crashed or stalled or something).
There are other flaws, but I feel I'm putting more effort into this review than the makers put into it's design.
Basically, this game defeats the fun of making choices to help your stable of warriors grow. It fails as an idle game.