Last updated 21 October 2026.
You need to be 13 or older to make an account. Keep your password to yourself; you're responsible for what happens on your account. A Family membership is for up to five people in one household.
Memberships are billed monthly in advance, through Stripe, until you cancel. You can cancel any time from your dashboard ("Manage billing"); you keep access until the end of the period you've paid for, and we don't refund part-months. If we change the price we'll tell you by email at least 30 days before it applies to you.
The games are for learning and enjoyment. They are not medical advice, and not a substitute for a doctor, a course or a textbook. We work hard to get the science right, but we can make mistakes; tell us if you find one.
The games, their stories, art and music belong to huangetal.org. Your membership lets you play them; please don't copy, resell or redistribute them.
Don't try to get around the paywall, break the site, or interfere with other people's use of it. We may close accounts that do.