Thank you for the feedback, that’s invaluable for me! The new procedural waves will need some more balancing for sure; in 1.5.1-beta I added a flag so roughly 1 of 5 waves will have no ranged enemies in it to give you the breather you mentioned. Maybe that number is still too low though.
I also plan to finetune the difficulty levels further, I too think that they’re too hard at the moment. But then again there’s supposed to be some grind: you should need some time and luck to actually nail Overload 20.
Keep the feedback coming, mate!