I am convinced f-zero and metroid are in the same universe, in the core you have big cities, the ultimate motor-sport, and bounty-hunters like capt falcon, on the periphery, dead civilizations, space pirates, and bounty hunters like Samus Aaron.

Now, admittedly, this is mainly based on them being based in the far future and having the same art style. But you have to admit Samus would not look out of place racing in Big-Blue