Appreciate the response. I gave the new build a try, but wave 11 was still basically a death screen. I can believe your tester finds the game easy, because I did as well all the way up until that point, but it sounds from your message like wave 11 isn’t meant to be the current end of content, so I’m not sure what I’m doing differently.
I won’t have any free time to play for a long while after this, but I’ll share my experience from this time as playtest feedback in case you find it useful:
I survived until wave 11 without getting hit, with a bunch of flame towers with the extra short range fire attack, always-away-from-princess knockback, higher knockback, multiple damage upgrades, player ice aura, I think a flame loop?, and emergency player speed to both quickly kill enemies & keep them away from center as long as possible. (fire was the last type of tower I tried out of all of them my previous playing, but it ended up feeling the strongest) When wave 11 hit, anticipating a lot of “big enemies”, I ran around with my emergency speed quickly hitting and ice aura-ing each to slow them and give me more time to damage them and have the fire do its thing. I did what felt like significant damage to them and I might have killed one there right at the end, but it didn’t really matter because they all steamrolled past my slow aura and flame tower knockback wall, collectively doing enough damage to KO me nearly instantly. It gave a strong impression that the wave is intended to not be able to be beaten. Having tried this with several builds, I’m not sure what you’re doing differently that makes it trivial, but hopefully you find a way to guide future players towards the solution. Good luck with your game.