Investigators released surveillance video of the robbery at the Game Stop at 2900 North Broad Street at 1:50 p.m. on Monday.
According to police, two employees were on duty when an unknown man entered the store and wandered around for about 20 minutes.
When one of the employees went on break, police say the man approached the counter with a handgun and demanded money from the cash register - and a PlayStation 3, which retails for about $250.
The clerk gave the man $250 in cash, along with the PlayStation, and the man fled on foot north on Broad Street.
The suspect is described as a black male between 20 and 30 years old, standing 5'8" tall and weighing about 165 pounds. Police say he has a dark complexion, short hair and a goatee. He was wearing a black hoodie and faded black jeans.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS or online at phillypolice.com.