Unlike pplord..., I was too busy enjoying the puzzles to finish them! (jk)
Beautiful representations of The Act.
(The only "off" picture for me is the title image, where she looks waaaay too young even by cartoon/hentai standards ~ also technically there's something about the sole of her foot and her toes that's weird .... overshaped on the bones/joints or something, toes overlong and separated like fingers?) The rest of the girls are top hentai. Even though the doll-like quality of faces is (for me, again - just a view) not the greatest feature of hentai, it's probably not the faces people are looking at so much anyway (in the stylisations of hentai - real life is a bit different, *cough*). The girl with the pumpkin overhead mask is sensational.
The only adjustment I'd suggest is giving the player a "reward", with a little simple animation on the completion of each image. About 12 frames each on a loop should be smooth enough! (No need for massive long brutal thrusts, just gentle jogging.)
To the issue, is it way too simple? I'd say no. We're not really here for slider puzzle solving, surely? ;)