i really really really like this resource based upgrade system but there are a lot of bad things in this game,just to give some example launch height is quite useless and if it wasn't spin levels over 6 would still be useless because 6 is enough to reach max height,it's impossible to stop a run,etc etc etc...i hope so much to see a second chapter with the same concept but a better gameplay design 3.5/5
for those having trouble,
1)bring all your ranged units
2)block inferno with buildings such as castle or wall
3)swordman->just bring fast units like goblin to block it
4)when nothing i said before works(it only happened to me on iron fortress bring vampires and all the epic units you have and use the vampire's regen spell to heal
in any case,charge->block hero->go take a coffe if you don't need to regen