Unlock Sly Joker
To unlock a fifth car, the Sly Joker, beat the Pawn, Knight and Bishop series on Standard difficulty.
Unlock The Stingray
To unlock the second hidden car, the excellent Stingray, you have to beat all Pawn, Knight and Bishop tracks on Expert difficulty. Good luck. You'll need it.
Unlock Silver Thunder
To unlock the super-fast but a little less stable Silver Thunder car, you need to complete the Queen Series.
Unlock Falcon MK-II
You thought that was it, eh? Nope, here's yet another cool hidden F-Zero racer: the Falcon MK-II. To get it, you need to beat the Pawn, Knight, Bishop AND Queen series on Expert difficulty.
Unlock Fighting Comet
And just when you thought they'd run out of cars -- here comes the Fighting Comet. But you need to work to unlock it. Beat every series on the Master Class difficulty.
Unlock Jet Vermilion
Here's the ultimate F-Zero racer. Jet Vermilion is insanely fast when you're boosting and has the strongest body out of all of the machines -- but it's so hard to get, most gamers will give up and run away in horror. You have to actually complete each racing series on Master difficulty with each machine (chess icons next to the track selection screen show you which series you have already beaten with the respective racer). If that sounds too difficult, you can also unlock Vermilion by completing the championship 255 times. Which one sounds more appealing? Good luck.
Unlock the Queen Series
Like the Stingray car, the Queen Series (with five additional courses set on Crater Land, East Ten Side, Laputan Colony, and two tracks on Fire Field) is unlocked by beating all Pawn, Knight and Bishop tracks on Expert difficulty.
Nintendo has designed F-Zero with tournament play in mind. Since you can't upload your best times or take screenshots, the game features a built-in ranking password system. To obtain an encrypted password for your best track times, select Course Ranking from the main menu, then select your name and the track you would like to get a password for. Now hold the L-Button and press up, right, right, B, left, B, A. Your tournament entry password will now appear at the top of the screen and you can write it down. Nintendo uses passwords like these to let you enter into official tournaments, so keep an eye out for them.
Unlock Championship Mode
Not to be confused with the standard Grand Prix Mode, Championship is a hidden option that lets you race a Time Attack challenge against a ghost car on a specialy Synobazz track. The mode also offers the ability to see a replay of the winning run, complete with button commands display. To unlock it, register your name in the rankings of every race in every series.
Unlock Master Difficulty
To open up the hidden Master difficult level (in addition to (Beginner, Standard and Expert), you have to first beat a series' Expert difficulty level in the Grand Prix Mode. Note that this will unlock the Master setting only for that series. You still have to beat the Expert setting on the other cups as well to get access to all the Master classes