Hot Wheels: Race Off is a Trials-style game of driving in one direction on a physically impossible track while trying not to wipe out. It's simple to get into, tough to actually play well, and aside from a handful of annoyances it's pretty fun. So long as you don't run out of gas, anyway.
Simply reaching the finish line can be a challenge in itself – let alone getting there in the fastest time.
Upgrade your car whenever you can. The more you upgrade the easier (generally) it'll be to get it to do what you want. It'll also make it easier to reach the end of the track, or even come in first.
Speed is the most important upgrade if you want to win. Just about everything else (grip, tilt, etc) can be adjusted for, but if you're too slow there's no way you'll reach the top time on a given track. The other stuff certainly helps, though, don't get me wrong.
Special coins can be anywhere. They can be tucked away in hard to reach alternate paths, or even hidden inside regular brick blocks. Keep a sharp eye.
Unlock new vehicles by fully upgrading others. I mean the option is there, so why not?
The race won't start until you do. If you don't hit the gas, the race won't start. Use this to your advantage and try to get the lay of what little land you can see before you begin.
Keep moving. You have a limited amount of fuel, which is always draining during the race. Dawdling wastes precious whatever it is little toy cars use for gas.
Always grab gas cans. Each track has at least one, usually somewhere around the halfway mark, and nabbing it will completely top off your fuel. If you miss it, chances are you're never going to reach the finish line.
You don't have to accelerate at all times. In fact, don't. Sometimes you're better off letting momentum and/or gravity do the work for you – both because it'll save a bit of fuel and because it's very easy to accidentally overcompensate during a jump and get yourself exploded.
Always remember the right pedal tilts back and the left pedal tilts forward. For some reason this always gives me trouble.
Grab those coins! Any and all coins you collect during a race will stick with you even if you fail or wipe out. This means no attempt is truly wasted, and you can save up and use those coins to upgrade your cars (as mentioned above).
More: Hot Wheels Race Off Tips, Cheats and Strategies [Gamezebo]
Uphill Both Ways
I couldn't really call Hot Wheels: Race Off 'special' or 'unique', but it does what it does well enough. If you're more interested in cars over motorcycles, prefer colorful and cartoony visuals over gritty realistic ones, or just have some time to kill and like physics and racing, you might want to give it a look.