What are some game series that have a surprising lack of certain spin-offs?
I'll go to Pokemon as an example. You have
>Puzzle Spin-offs (Pokemon Puzzle League)
>A Trading Card Game (Pokemon Trading Card Game)
>A (kinda) fighting game (Pokken)
>An on-rails photography game (Pokemon Snap)
>A pinball game (Pokemon Pinball series)
>A virtual pet game (Hey you, Pikachu)
>A tv watching simulator (Pokemon Channel)
>RPG games (Stadium, Colosseum, Battle Revolution)
>Circle drawing (Pokemon Ranger)
>AR games (Pokemon Go)
>Simple action games (Mystery Dungeon series and Rumble)
>Strategy games (Pokemon Conquest)
So there are a ton of spin-offs, and a lot of them are weird and don't quite fit any genre too easily. But even with all these games and series, you don't have any examples from a number of genres that are usually no-brainers for spin-offs. For example:
<No minigame collection/party games
<No racing games
<No platformers
<No sports games