It is in very good condition for being as old as it is. All the buttons work and the battery lasts a long time.
It has probably been in storage for the past 8-10 years and it still turned on after not being charged for that long. The Gameboy comes with a charger, case and 6 games. It also has a precautions booklet for the Gameboy. The six games are as follows.
Kong The 8th Wonder of the World. Mat Hoffman's Pro BMX. The Kong game also comes with an instruction booklet and a map of Skull Island. Feel free to message me for additional details and/or pictures.