The LD community sometimes ends up having bonus themes in LDs such as Kittens or, this time, Goats, which can either be seen as an additional challenge or a useful inspiration. However, there’s no need to include them and people won’t – or at least shouldn’t – downvote your game due to a lack of goats. If you have spare time after finishing your game, you could add a goat character (not necessarily main character) or a secret goat bonus or something.