I played only the free version, so my judgement may be a little wrong.
This game was obviously inspired by "Drained By Cuteness" by MinMax3D, that has roughly the same story (vampire instead of a demoness) and gameplay (go for missions, fight enemies, gain reward points, even the same Armory - Mage Guild - Shrine - Guild buildings and upgrades in them).
Drained By Cuteness is absolutely free but features no art at all, and has much more basic design.
Overall i'd say that In Her Shadow is not worth the cost for the time being, but closer to the end of development i'd suggest coming up with your own missions/buildings/upgrades and it will become a solid game worth buying.