i've played a bit of "the heart" made by the same people, using the same system and largely compatible (from what i've heard) with "the spire" but that game is naturally a lot shorter (it's concerned with what your character wants and finding it so after like 10 sessions, pcs started either dying or leaving the adventuring life behind
i heard about the spire but sadly never got around to playing it; what do you like about it? how "deep" are you in the TTRPG rabbit hole?