The int and str heroes fall off hard in the late game and can't keep up with the mobs anymore, i suggest buffing their spells to scale with stats for all heroes! The heroes aren't balanced, some heroes are way stronger than others, the str heroes seem to be the weakest of them all! Either the 'normal' difficulty is bugged or not, i can't tell since is so insanely hard even on normal, either create a new difficulty easier than normal or decrease the hp on normal difficulty because the way it is now, is just impossible to beat the map!
Increase the time between rounds, they come too fast, the player doesn't have time to think! this td is pure utter bullshit! congrats map maker! i played on the easiest difficulty (which is normal) and i managed to die every time, always between lvl 40 and 47, even tho i literally did everything right, i even killed all the gold coins in the bonus lvl, like how even is that possible, getting all kills in the bonus lvl and dying in the next 15 levels, is just insane! In the end i used cheats just to see what was the end of all of this, and to my surprise even with infinite gold/wood my towers still kinda struggled versus the mobs somehow, that is insane!
i played it solo like 10 times and i must say, This is without a doubt the hardest td i've played in my life!