"being almost impossible to get to wave 50+". You wish you were right :D (might do more just to prove a point)
But seriously, great job with the performance, it works much better now (I wouldn't have gotten this far otherwise) <3. The infinite castle + steel cube combo is just way too strong.
Also, I've noticed a slight graphical bug - the king name and health bar seem to be slowly moving downwards as you get further in the game, eventually disappearing around lvl 70, see screenshot (it's not particularly important, but still, you might want to know)