Short, but never rushed or poorly fleshed out. Elegant choice mechanics whose juxtaposition creates lifelike nuance; an interesting spin on a common plot, and, lastly, beautiful prose- all resulting in a captivating game.
It's not rare for even monsters and inhuman threats to have some sort of value system and integrity of their own, making them more than a thoughtless obstacle for the protagonist, and I enjoyed the idea of the siren that manipulates and kills, yet only consumes prey that surrenders to her seduction of its own volition, rather than hunting ruthlessly, and is willing to engage in honest discussion and admission of her nature- but my favorite part is probably the love/lust passage upon choosing lust: the genuine smile and freely given parting kiss seem to not make sense unless read as an act of actual goodwill.
Even with her candidly admitting that parting ways unharmed is the best that can happen, and tangibly witnessing death in the other endings, it can be hard to shake the hope that where mutual goodwill and cordiality can be found, there can be coexistence; having apparent redeeming qualities only makes the monster more dangerously misleading, and it seems ironically rather unintentional by her.
(Of course, it's possible that I'm being a sucker, and she does this on purpose to make victims struggle less and give herself a less frightening reputation- but even then, it's interesting how this is achieved by genuine integrity, especially given that she doesn't seem to at all resent humans or revel in their pain, only feed on them.)