swapr: a simple arcade puzzle game

swapr is a very simple, but fascinating and addictive game which is easy to learn but hard to master.
This game challenges your reaction time as well as your eye-hand coordination.

But how is this game meant to be played?
The rules are simple:

Each colored column represents a lane. Blocks are falling down from the top of each lane. Your goal is to make the paddles at the bottom match the color of the falling block in that particular lane.
Quite simple, right?