Fun game, although it's a challenge to run it having never played Bloodborne. I ran a one-shot game through a version of Heliwyr heavily influenced by H. P. Lovecraft's Shadow Over Innsmouth, lots of watery critters and cthulhean "sirens", and that worked really well. The game could easily stretch out to something quite long, or play through very quickly, depending on player choices and how much RP is happening, so be prepared for that.
I Went to the North Pole Once is a great prompt game for the holidays! I played with my kid (4yo) and had a really fun time coming up with ideas together (many of his ideas revolved around nutcrackers and hot cocoa)!
I've got a full review here too on the TTRPGkids site: