I don't know how old this game is, but the version currently in the OP (scratch that, they updated OP while I was typing this) was some of the more high end 2D animation I've seen....or so I thought. That was until I found the updated version on page 2, that 2D animation raised the bar of 2D animation in sex games into the stratosphere and was a complete rework from it's predecessor that kind of quality change alone would warrent a decent chunk of time away from a project, not only to rework but to make the decision to scrap what you previously had created and replace it with what's currently there. Again, not sure how long the creator stepped away, but thank goodness they did.
Granted the combat and stages are the same, (aside from how some of the attacks look and function being reworked, I'm in love with how the new basic attack slows to a halt on enemies and explode upon finishing) the spikes are new though, the new enemies look gorgeous, and the end of stage purification is a nice touch, I'm sure he contemplated on whether to have them respawn or not and I'm glad he landed on the choice that he did.