Okay, so it's implied when Tom asks what your favorite animal is, [[spoiler:that's what you turn into. What if it's an amoeba or some really primitive predator, like a jellyfish?]]
* No answer for the jellyfish, but it's explicitly stated that [[spoiler:crossing turns you into an animal, and [[YouFailBiologyForever amoebas are protozoa]], not animals.]]
** [[spoiler:What if your favorite animal was an insect or arachnid? There haven't been any arthropod villagers thus far, so are there even Gyroids for those? Also what would happen with your limbs if you said your favorite animal was a snake...?]]
*** [[spoiler:In the snake case, presumably you would become a snake-headed humanoid. Not sure about the insects.]]
In the bad ending why didn't the [[spoiler: government arrive since Nook had already tipped them off.]]
* [[spoiler: It is possible that the government did arrive in the bad ending. Billy mentions temporarily hearing a "funny putter in the distance." That noise could have been the government's helicopter. Though I don't have any idea about what happened to the government agents when they arrived on the island.]]
* [[spoiler: In the final moments of the bad ending, Billy mentions that they got some new guard dogs. This troper took it that the government agents were somehow captured and assimilated.]]
* The Gyroids are based on Japanese Haniwa burial statues. Haniwa were placed on people's graves and were said to contain their souls. Suddenly the fact that they will curse you to undergo a horrific transformation as punishment for defiling their resting place makes a whole lot more sense.