I'm in a situation not exactly like this, but somewhat similair with the The Legend of Zelda and Metroid franchises.
I have two Zelda games (A Link Between Worlds and Twilight Princess (and Four Swords Anniversary Edition, but that one doesn't count) and four Metroid games (Metroid II: Return of Samus, Super Metroid, Metroid Prime Hunters and Metroid Prime 3: Corruption). I did enjoy all of them while playing them, but all of these games failed to really grasp me. I only played Metroid Prime Hunters and Metroid Prime 3: Corruption a couple of times, and the others I for whatever reason stopped going back to after playing them a few times.
I don't know why, I really want to love these games. I want to get involved in the series, especially the Metroid series. I love its settings, lore, characters, general astheatics, yet for some reason the games just fail to really grab me. Same with Zelda. I really want to like it, but I just don't have the drive to get into it. Maybe I have to play a little more of Twilight Princess to fall in love with it, but A Link Between Worlds failed to grab me. As for Metroid, who knows. On one hand I'd love to try and get back into it, but on the other hand I don't think I'll last that long before quitting again. It's a real shame, since I really want to love the Metroid series, but I just can't get into the games.