Good combat
Good writing
Good soundtrack
Good vanilla fetishes (no NTR, futa, furry, yes tomboys, gentle switching femdom, sort of harem, future ara ara and pregnancy)
Good art
Lovable characters (Metatron being super lovable)
The equipment system is a bit of a head-scratcher because in RPGs I tend to hunt artifacts and hoard gold, with crafting as much as possible if the game allows but DD apparently was not designed with that philosophy which honestly is not bad, just different.
I really don't have any constructive criticism, the best I could do is go turbo-anal over minor issues.
I will pay for the game when it is finished. I know you would prefer money now and then invest it in art or something but I am allergic to paying for an unfinished product, sorry.
Great game, looking forward to the future patches. I will recommend it when someone asks me about good h-games.