items:
currently eggs restore 10 hp and can be used infinitely. I don't know if this is intentional, but it completely breaks combat my having an infinite supply of health.
there are some items that seem like they should heal you but do not, such as milk. this would also add a way to incentivise players to use these items.
I feel like there should a clothing item to conceal the eyes, unless this is a deliberate design choice.
if there is going to be a staining mechanic, i feel there should be a way to clean the clothes

species:
the player's species should affects stats more(like how the slider does 10% more damage)
custom flavor text for attacks
unique species abilities would make things more interesting
udder size should have it's own value besides engorgement, like the breasts.

debug:
some transformations (horse, whale, slug, frog, tiger, and bunny) are not available in the debug room.
a curse/item removal tool would be useful
there should be treasure chest to let you quickly get money in the debug room
the weight testing room has a way to increase weight, but not decrease it.
there should be a way to replenish items in the debug rooms of they are all depleted
one of the teleports should go to your apartment

modding:
when in debug view, i've noticed that whenever the game makes a comparison, it will say that the result was false, even if it was true. it will proceed normally, but this makes checking if things are being triggered difficult.
allow modders to start pregnancies. i have several mods in the works that can't go forward due to this
please, PLEASE let us create dialog boxes or menus
the ability to bundle mods together in one package would allow for the creation of complex and large add-ons without cluttering the mod browser, and so you don't have to load each asset individually
status effects would allow for lots of different things, such as the obvious, as well as more interesting things like temporary heat/regen/boost items or delayed activation