Rather than a game, Kno is a tool to assist you in a specific kind of mindfulness meditation. After creating an account with the game, you can log in and start a meditation session. During this session, which will last as long as you want it to, you are asked to type single words representing whatever is drifting through your mind at the time. The words turn into glowing drops of light. Most drops are white, but if you type a very positive word ("joy", "happy") the drop will glow green, and if you type a negative word ("sad", "hate") it will glow red. When you're done with your session, you can use the drops to water your "tree of thoughts," which very slowly will grow over multiple sessions (it takes 2,000 words to get your tree to 100%) until it reaches its full growth, at which point it will get stored and you can start a new tree. 

Graphics and interface are clean and minimal. The bgm is calming, with soft water drop sound effects while typing. If you're looking for something to encourage mindfulness and meditation, this program is worth trying out to see if it works for you.