Stop the cube aliens flying out of the portal and trying to escape to the universe.
Shoot as many blue and red cubes as possible in the time limit given by a playing song. But be careful! You have to shoot ret or blue cubes by the right gun as the corresponding color.
Check your perception, improve your agility and reaction speed.
Music by: https://soundcloud.com/liqwyd
Audio effects from http://soundbible.com/