A game I keep playing without realizing it, drawn in by the atmosphere

If you look at just the gameplay, it's a pretty simple game. It's easy because you can raise characters passively, but it might be a bit lacking for those who want a game where they "personally control and conquer challenges." However, the world-building, music, and characters are just great. Each character has a dedicated song, and when you listen to it after learning their background, it really hits home. It often starts with "I like this character," and before you know it, you've come to like their music too. Since raising characters is also mostly passive, it's a relief that you can progress little by little even when you're busy, right? Of course, there are aspects to consider like gacha, progression walls, and monetization, and you might feel it gets repetitive after playing for a long time. Still, just logging in, looking at my favorite characters, and listening to the music is somehow satisfying. Including that aspect, I think Memento Mori is a quite unique and charming work.