I added these instructions to the game description page:
Keep the viruses away from the top of the screen where your health structure is. Drop mines with Z and X. Wait until the viruses get close and detonate the mines with the same button. Z is the left paddle, and X is the right one. Move back and forth with LEFT and RIGHT.
The viruses increase in number and speed after each wave, and you also recover some health. Each new wave generates a new hexagram, and its explanation scrolls in the yellow area below the health structure. These explanations are the result of your consultation with the oracle I Ching or Book of Changes.