Form a line of 2 pills of the same color (clicking on them to switch between colors) + a kaguya-virus of the same color (you can move the kaguya-virus with the mouse)
Story Teruyo-san went to Yagokoro to get cured for an illness, but Yagokoro started administering a ridiculous amount of medicines in an attempt to give her eternal life and youth. Please control the pathogenic germs inside Teruyo and resist the onslaught so that she does not gain eternal life and youth.
Kaguya/Teruyo * She's the protagonist of this game, but all the poor thing does is sit there as she's made to swallow medicines over and over.
Yagokoro Tosses one capsule after another. As time passes, she increases the rate of administration. Fiend.
Capsules Contain Hourai drugs. Click to swap the left and right sides. When they heap up to the top of Teruyo's mouth, it's game over. Apparently, rather than eternal life and youth, she gets death by overdose.
Pathogenic germs Move them with a mouse click.
You can make the capsules disappear by lining up vertically with a germ two or more capsules of the same color. You get more points by clearing more capsules at the same time, and by having the germ at a higher position when they are cleared. (If you make a line of the same color using only capsules, they won't disappear.)
(*: "Teruyo" is a nickname that fans came up with by using alternate readings for the kanji that make up Kaguya's name.)