Speaking of weird niches: INFRA ($15 on Steam) is an exploration/adventure game where you play as "a structural analyst on a routine mission." That's a direct quote from the Steam page. Your job is to explore the less-accessible parts of a town's infrastructure and photograph anything that's decaying or dangerous: Cracked bridge, rusty support beam, et cetera.
Or, at least, that's the set-up. Spoiler: Things are more than they seem.
INFRA is weird and sometimes a bit busted but it can also be exceedingly clever at times, with an amazing attention to detail that most games don't possess. Plus, there's something fascinating about playing a game as an actual person, not Joe/Jane Superhero. My only qualm is that only the first part of the game is out now. On the other hand, Part 2 is supposed to be free to all current owners when it eventually releases.