Good morning!
I hope this is the correct place for my suggestion.
First of all, i want to say that YouTD became my favourite Tower Defense of all.
Since im a huge Diablo fan, i always like the chance of finding rare items.
But i always would have liked the chance of a really, REALLY rare item. In Diablo i wished they include Artifacts which could have the color red.
Same now in YouTD. Towers and items go up to Epic. Is it possible to add legendarys? Items only a few and towers maybe only one per element.
I'm not into programming stuff or generate such things and keep at leats a kind of balance so i don't know if this is too much work or changes too much.
So it's just a suggestion to make a perfekt game godlike imho.

Sincerely,
Mordavian