The animation is superb. I really like it how her lips conform to the shape of the penis. It makes the game feel a lot more realistic. I also love how her expression varies from time to time, and the sound is pretty good too.
The only thing I dislike is how static and unchanging the penis looks. It doesn't actually move at all. It would be a lot nicer if the dick moved a little bit with her head, similar to how it looks in Konashion's flash game Super Deep Throat.
Regardless, I think this deserves 5 stars. This has got to be the best thing I've seen from you yet.