OK, this game needs three things:
1) The ability to give movement commands to your troops (even just simple ones like "go forward", "go back" and "stop").
2) Some mechanic to force you to use these controls (say, an enemy that sits out of range behind a bunch of trash mobs and shoots long range projectiles at your troops, spawns fast flyers flyers, etc.)
3) Enemies that spawn on your flanks or behind you from hidden spawn points to ambush you once you've gone after said artillery or whatever.
Or at least just come up with an enemy that counters the handgunners. If you have a line of those on either side of the defense point (and you can, because they're cheap), you can hit "start", go get a coffee, and come back and your characters will have won the game for you 9 times out of 10.
Also while having enemies spawn from two sides does make the gameplay a bit more interesting, the result is that most of the time when your troops get raped it happens off screen. I think having them spawn on one side, but then use the mechanics above to force the player to split their attention between leading counterattacks and running back to protect their flanks would have been way better (if probably harder to code).
I should probably have prefaced this by saying I did like it though.
