To play Doodle Jump, simply move left to right to reach the platforms. To fire, use the left mouse button. The gameplay is infinite, so jump as long as you can to get the highest score.
There are various ways to travel faster and increase your score faster in Doodle Jump. The first method is to use the springs to propel your small alien higher. You'll also come across rocket boosters and a propeller cap, which can help you get higher.
Along with boosters that launch your alien to greater heights, there are barriers that give an extra difficulty to the gameplay. The first danger you'll face is brown platforms that break when touched, but this is a minor issue. The most concerning threats are aliens and black holes.