Up arrow to go up, down arrow to go down. A new ball spawns every 10 points you get until you get to 100 (which is very hard). The balls move faster as you get more points and will also be quicker to fire at you when you go along.
Coded completely by me for school. Just a straightforward game I made. Sounds downloaded from here: https://freesound.org/people/LittleRobotSoundFactory/packs/16681/ Music: Eric Skiff - Jumpshot - Resistor Anthems - Available at http://EricSkiff.com/music