Two buttons was the theme I chose for Ludum Dare 34 (out of two choices, two buttons and grow)
You can click either side of the screen or press the arrow keys/a and d to move to the left and right. Try to catch black spheres while moving right and white spheres while moving left.
If you touch the wrong color, it's game over!
If you would like to vote on my entry to Ludum Dare 34, here's my link.