So like,
Undertale?
I mean, it’s definitely a heavy-handed Press X To Kill Your Friends kind of game, but there are a lot of small things that you can do that impact your game later but aren’t really obvious. In particular, I’m thinking of flowey berating you for killing toriel, then loading your save game and sparing her.
Are we still spoilering undertale?
Anyway, most of the things that aren’t signposted are things that don’t really change your game in a significant way, but it changes or unlocks tons of weird optional text or encounters. The amount of detail in that game is incredible.
EDIT: Okay I found this thing: If you tell the frog that you don’t like yellow names, he’ll offer to get rid of them. (Monsters that you can spare have yellow names) If you then talk to him again and say you want them back, he says that everyone already threw away their yellow names, but they still have last year’s pink names they can use instead. For the rest of the playthrough, monsters you can spare have pink names. Later on, if you examine a garbage pile in the trash heap, it’ll mention there’s a pile of yellow names.