Yo this is awesome, controlled body growth like this is exactly my thing, especially ones that don't force you to become fully female and etc.
Personally I enjoy the 3D models used here, and I think that it allows for more variety in body sizes and etc than 2D would. The model used here looks quite nice, especially compared to how early humans in animation looked uncanny.
If I were to make some changes, it'd be to add more text, whether in terms of dialogue between you and your alien hypnotist, or just instruction in general. Maybe a few more poses or other 3D elements as well?
The hypnosis system works well, even if it's not immediately clear what each "layer" does. Something I've had issues with is selecting which "layer" to switch directions of, and I often end up selecting the wrong one. Being able to use numbers on the keyboard or having a cursor visible may help make it easier, but also I may be missing something.
There's a lot of potential here, and if you continue working on this after the Strawberry Jam I'd love to see what you do! I'll be seeing what other sorts of games you come up with too, because these and your other games are quite a treat.