I really like it. The only gripe I have with it, and I suspect many others do too, is it's round structure. It makes it feel sort of repetitive having to repeatedly play 7 or 10 rounds. If you can survive 20 rounds, it would be better to have the option of where to place the end boss, rather than playing two or three games.
Sometimes seven rounds is all you fancy, but when you're playing in a capable party, completion feels disruptive.