It took me around 1 and a half hours to beat the game.
It's interesting. The difficulty scales really well.
Most of the problems of the game are caused by the way your character moves, it's a bit clunky at times.
Though I wouldn't lie, I loved the concept, and appreciate every demon. The character design is really great, I wish I could spend more time with the demons. The only issue is that the sex scenes last too little.