Playing with the new endless mode is fun, I like the changes to flying. I think that so far for me, the biggest thing has been some of the clarity on what certain keywords mean. There is a perk for I believe it was "Invoke" or "Conjure" or something of the sort and I don't know what that applies to.
Maybe giving either a key to look at or a tooltip on hover for some of those keywords would help give some clarity to what they apply to. I also will parrot some of the other commenters on here that mention its hard to get an interesting run outside of endless mode. I find myself getting to 50-60 before my run actually ends. Maybe some more waves would allow some interesting builds to be created before hopping into endless.
Regarding the first point...I'm cooking something up that should help with that. And regarding the second, I'll just need some more time to come up with new enemy types and stuff. But yeah that will all get added!
In the meantime, I suggest joining the discord. There are quite a few discussions about balancing and improvements to UI, bugs etc. on a regular basis. Much easier to discuss there than here :) Thanks for playing and your feedback!