Tap the screen, or press space to jump. But make sure you time your jumps precisely! You can even hold your finger on the screen, or hold down space to jump repeatedly. (Or fly up, if you're in a rocket) Look out for spikes, if you touch them you will be Glad you will entertain with Geometrical Dash!
You can play the game on phone and tablet, such as iPhone, iPad, Samsung, Amazon, LG and other Apple and android operate system, enjoy!