In dino run how do you unlock planet d

You have to go to the insane challenge,but when you are at the big valcano,don't go to the Secret Survival or the Pardise,if you do then you are never going to unlock the Planet D.So ignore going to the Secret Survival/Paradise,just go straight ahead.After you finish the level 7 of the insane challenge,yu will notice that u get to a level called 'beyond apocolypse' and there is no background but keep on going unless you don't want to unlock Planet D or you want to be doomed/extinct for no reason.When you reached the end, you will see a spaceship,go inside adn you've unlocked Planet D! The final super egg, 'diplo' will also be there!