That's quite a compliment! Thanks!
I had to fit it within 30 minutes of play time because of the jam rules, but the original plan was that the "back-and-forth" go on for 4~5 times. The choices young Lydia made would influence what events occurred on the ghost ship, and the choices made during those events would in turn influence the choices available to young Lydia. After finishing the intro scene I realized it's never gonna fit (like, duh!), so changed it to the linear, story-driven format that it is now. Might revisit the concept in the future though.
There is a short bonus cutscene if you win the battle, yes... so if you happen to have a save just before that, please do give it a go. I don't think it's particularly hard as long as Lydia stays alive long enough to do her part (which, admittedly, requires some luck).