Pitch of the game
"-Haha, i'm gonna be such a pain in the ass with my reapers, i probably can wreck this noob in less than 4 minuts"
"-Calm down ya little boy"
The main goal here is to cancel the early reaper scooting and pressure with concussive shells. Then play aggressively with your four marauders to scoot for potential banshees, make your opponent over react ("OMG i need bunkers and widow mines and stuff") and mess his build order.
With this build order we are vulnerable to early Banshees all-Ins. This is why an engineering bay is recquired fast enough, plus a Cyclone.
Rush the 1st Medivac and the Stimpack, then drop your opponent with your four marauders.
If you didn't finished him yet, well, you have an expand and most of your tech tree available. You can now add barracks, and prepare for macro game =)