If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Swap the objects to bring a line of 3 or more identical bacteria. In every level reach the target before time ends to swap bacteria in tougher levels. If you feel it hard to swap use hint option to know the swappable bacterias but using the hint option once will reduce 50 points from your score.
This game is played with mouse only.