Urhhhgg
theres a glitch on the round with after you get the mass arrow attack where a spearman is only killable in one tiny spot (all others simply pass through him)
and as the waves increase in difficulty, you have to award more experience, as i noticed that you only recieve exp depending on your headshots percentage, but in later waves the powerups are necessary to succeed and don't award headshots.
otherwise great game
O ya YOU NEEEED SAVEPOINTS