Very simple game concept, but excellent execution and presentation! It plays exactly like it should, there's even quests to have the players challenge themselves and change things up.
The animations are smooth, the models look great and there's all sorts of cool visual effects to make the game satisfying. Only area that can be reworked a bit is the point of penetration, since that's the main focus and it's got some clipping happening.
Sound design is great, you've got a good range of moans that feel responsive to your performance. The music is also varied, fitting and upbeat and has a nice fadeout effect for failure!