Coins
Save coins to purchase new ships. Each will have gradually increased fuel capacities. After landing on new checkpoints, you will have an option to watch a video advertisement or pay a fee in coins to activate it. Consider watching the advertisements to get the extra fuel. Coins will also refill a small amount of your ship's fuel. This is the only way to pass through long areas without a checkpoints. Also collect the blue diamonds, which are worth 100 coins each.
Fuel
If you run out of fuel in midflight, you will crash land and have the choice to watch a video advertisement to continue. If you decline, you will resume from the last checkpoint. There is no limit to how many advertisements you can watch.
Hidden areas
Suspiciously placed coins, such a single one in front of a damaged wall, can reveal the location of a hidden area. Try flying into the wall to check the presence of a hidden area, which usually contain diamonds.
