Use the arrow keys to move and jump. Press DOWN while running to slide. Jump while sliding to go further in the air. Press DOWN while you are in the air to smash, which lets you go through transparent platforms.
You can also jump higher by jumping right after you smash, or by standing next to a wall while you jump. Do a wall jump by pressing UP while sliding down a wall.
Reach the flag as quickly as you can. Grab the bonus coins to unlock skins which you can select on the main menu.
Use arrow keys to move.