1 star because it cant be played inactive and what I mean about that it should be still playable when you exit/turn off the game and the game itself starts collecting resources/upgrading, I cant just stand and watch the game just collecting 500-1000+ resources for 3-5 mins maybe even 7 mins or more thats just gonna drain my phone battery, it really needs a inactivity idle gameplay than watching/waiting for them just to collect it gets boring fast