If a Metroid spin-off game were to be made by Nintendo, what would you like it to be?

No mainline games, no Prime games, not even remakes or reboots of older games. A completely new Metroid spin-off. It could have the same gameplay with different characters and location or we could see Samus in a whole different game. Pinball demonstrates that the possibilities are endless.

So, which is your wildest Metroid dream?