actualy I got moon with 38 mines and mars titan and europa 38 as well most gaining from europa equal amount of mines planets on next tier bring greater gain each click :)))
@quizer & mysticwave: unneed not need to jump more than two squares thats why you have to dig wisely
however is hard objective really hard ?? I finished game in 15 hours about no objectives left fully upgraded used tons of dynamites and teleporters :D
and there must be a system to build materials fast I bored while I'm upgrading to tier 5 its like a torture