Was fun at first. So many ads though. I bought the ad free package. More and more resources needed and harder and harder to collect. Grind and grind, for what purpose? To grind some more. No goal, no achievements. After the 2nd portal I was forced into an additional purchase or go back to a previous planet and grind a resource that was already hard to collect. This whole game is a cash grab with no purpose. Lost it's luster pretty quickly.