Though I despise making this kind of feedback (won't argue), this would make an opportunity on fixing up things that can go wrong for others.
The game was played thrice and found two bugs, and one opinion on making the game better:
Bug 1 - The pause menu is unreachable once you reach gate #13. The M key is useless after this point of the game. This was tested during each gate during the 3rd playthrough to determine where it stops bringing up the menu.
Bug 2 - The pregnancies stop occurring once you reach gate #13. It is interesting to know which creature does procreate where, but the creatures after reaching this spot, nobody would know how the rest procreate, if so. This discovery was on the 3rd playthrough, procreating with every new creature passing each new gate, same with old ones to determine if any stop specifically where.
Opinion - I beat the game without 'reproducing' (2nd playthrough), and while the ending is all the same, it would be cool for alternate endings (ex. just walking out without 'reproducing' or leading other creatures outside if the player completely warps the character's body).
I would play this game again if there comes updated versions that would have these fixed (and altered, if possible).