I was a playtester on this, and can speak pretty roundly in favor of it.
Haghorse Run is a classical style train adventure that is complicated by the fact that it's running in Footfall, so when the turn does come and Things Happen, everyone involved is a physics-ninja.
This both means that Haghorse Run can go more literally and metaphorically off the rails without imploding, and also that the suspense leading up to that moment feels more interesting. There's a real sense of tempo as the PCs and NPCs start exerting more and more influence as they get a sense for the social and physical landscape of the train, and there's a lot of little mysteries to solve or entirely miss. Genuinely, this is one of those adventures where it'll never run the same way twice.
In terms of polish, the version I playtested was pretty full of features but there's been a lot of small stuff added since then. My favorite bit of enrichment for a train scenarios is a period appropriate menu, and Haghorse has one. For maximum immersion, you can try to cook it yourself.
In terms of who this adventure will resonate the most with, I think people who play Footfall like it's Outlast might not vibe as much with the more gradual pace, but if you like mysteries and pseudo-historical RP and stuff like Horror On The Orient Express you'll have an excellent time.

































































































































































































































































































































