Play Mass Effect: meet exotic new species, shoot them in the face with lasers. Like other AAA titles, the game is padded out with busy work to prevent you from having all of the fun in one sitting. So, cruise to exotic new planets, run routine surface scans on them, send probes, purchase upgrades for your scanner, etc. Basically, stuff that computers are really good at.
Fun fact: the dev team included an easter egg if you probe Uranus. What can I say? They know their audience.