Justin actually made this as a way to poke fun at the idea of getting cease and desist letters. At the time (October 2006) he had nothing to lose and his original intention was to call this "back to the future: the new official universal studios cartoon featuring the new Doc Brown and Marty McFly" and then just sit back and wait for a letter from their lawyers to arrive. That's actually why it's so filthy. He was just looking to "troll" a big studio. 7 years later, hit new animated TV show on adult swim.
When Morty thinks Rick's adventures are too dangerous, he challenges Rick to let him lead one instead. Before heading out on Morty's quest, Rick caves to pleas from the rest of the Smith family to help them solve mundane tasks and leaves with them the Meeseeks Box, a gadget that will instantaneously summon helpers named Mr. Meeseeks.
After crashing into their living room, Rick sends Morty off to make clones of the now-deceased Simpsons. This episode's "couch gag" was the longest in the history of The Simpsons. In addition to Rick and Morty's cameos, there are Futurama easter eggs to look for!