A lot of interesting combo's to win
I loved it! I'm still playing around with Combo's. hard mode was difficult at first, having to click on "next wave" immediately to ensure the highest possible bonus. I had instant deaths of course, and tried teleporters + splash poison at the beginning to see how much I could bring the creatures down before they reached my other towers and it worked decently. was just playing around. wish I had known some of these combos before I really started though, Definitely gonna have to play around more ;)
The 4k tower definitely needs some added bonus. even 2 slots would give it a decent edge. (that attack speed with double damage, slowing affects or quicker reload would be intense)