Fzero. Just the best damn high speed racing series ever.
The original one is fairly mediocre these days, but Fzero 99 breathed new life into it by making it massively multiplayer. Fzero X was amazing on N64 and still shines today on NSO, not having lost any luster over the intervening quarter century. And of course Fzero GX was an incredible game.
Fzero really is the best thing in the whole gaming industry for what it does. And yet, due to Nintendo ignoring the series for the past two decades it is not a small nearly lost IP.







