Great game, but I have a few criticisms/suggestions:
-If you intend for the player to engage the sins in a certain order, make it more clear what that order is or make it linear
-I think you should have the gallery appearance/description for an area-specific enemy be unlocked after you beat the boss (for example the succubus are in the gallery after you defeat lust)
-It'd be cool if in the future (when all the domains are complete) to have a custom endless mode where you can enable/disable certain enemies