The bottom left virus is activated. Every virus of the same color it touches becomes activated too. You can change the activated color by use the left and right keys. Activate all viruses in less than the desired moves, and you win!

This game ranked 2nd place in the recently held PDROMS #3.667 coding competition. Thanks to birslip for this submission.

http://www.pdroms.de/phpbb/viewtopic.php?f=53&t=381