If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
You have to eliminate viruses through skilled use of the right pills. Similar to the old Nintendo classic "Dr. Mario". All viruses have to be eliminated. If there are at least 4 pills and/or viruses in one vertical row, they are eliminated. Mind the live monitor! All viruses have to be destroyed before the monitor shows a complete infection of the body.