With no explanations for the gameplay mechanics I found it hard to understand a lot of things. Stars or Toolkit??? What does the hidden key unlock? Racing is rather dull - apart from the powerups there is little to do.
Stars & Toolkits= purely cosmetic effects. They're those color glows when you boost. Hidden keys unlock shortcuts.
Also: Boost Start= step on gas pedal the moment the lights go green. Boost jump= tap gas pedal the moment you land after jump. KERS boost= on the blue/white starry parts of the track, hold down the gas to accumulate boost. Let go of gas after the first block is charged and repeat for the 2nd and 3rd blocks to get maximum charge.
There is one thing that I don't know if it's possible on this game, to do sharp corners, seriously there are some races that I lost only because I couldn't do the corners properly, and don't say that F1 Cars can't do powerslides, Ayrton Senna did a lot of them while alive (even though the F1 cars at that time didn't had the same amount of grip of nowadays cars).
I don't think it's possible without slowing down. Which is one of the reasons i think the AI is cheating at the beginning of the Belgium track right after the 1st KERS corner; they could all boost perfectly into the shortcut while I helplessly slam into the wall thanks to the lv3 KERS boost.