The title implies a transactional or somewhat tragic arrangement ("In place of that girl"). This feature forces the player to confront the morality of that arrangement. It turns the "substitute lover" trope into a psychological puzzle about grief, projection, and identity.
To emphasize the theme, unlock a in the CG Gallery. ano ko no kawari ni suki na dake telegram
(e.g., a channel description), please share more detail, and I can help you interpret the Japanese or find a legal alternative. The title implies a transactional or somewhat tragic