BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
You are an Imperial soldier. A revolt has begun on Boonda the Hutt's moon. The leader of the revolution is the devious droid Wuntoo Forcee Forwun. His army is made up of hundreds of droids... and they are all prepared to kill on sight. Your mission: to stop the battle droids before they take on the Empire.