In the game you have to avoid all planet to don' get damage. The red and big one not damaging instantly but it is increasing gas level. When gas level increased, you have to avoid gas. If you stay 2 second in gas you will get damage. Other planets give damage instantly.  There are Blue wishes in the game. If you collect 3 of them, you will refill your health and double your current score. They are also looks like planet but they are very small. You will understand when you see. 

By the time game gets harder. Player will move faster and planets will increase.

In the game there is no sound and tutorial. I couldn't make it because of the time.