It is a puzzle game where the objective is to defeat different colored germs using vitamins of the same color. It is basically four in a row just like Tetris (row or column counts) or to put it another way, to defeat each germ, three halves of the same color must be next to the germ. These halves do not need to be on the same pill. The germs will multiply as the levels progress.
The germs come in three colors: red, yellow, and blue. The red and blue ones are named Fever and Chill (respectively), after the two music tracks provided, while the yellow one is named Weird.