i don't see formamorph as a game engine but rather as a AI simulator. You give it a context as complex as you want and it tries to bring it to life
i'm using a code ripped and edited from Entwinted Verdancy (FireyLion previous game) if you want to try and use it as a base or see what could be improved.
If you want specifications to starts from 0:
Objective: try to not get transformed into a host of the latex entities (like the enemies of Latex Dungeon)
Entities: latex blobs, the color indicates what shape they prefer. (Purple: animals/none. Red: tentacles. Etc)
Body modification: after or during an encounter your body is modified, similar to the infestation level on your character in Latex Dungeon.
I don't mind the images, endings or other stuff so you that's on you to decide.
Thanks for your cooperation.