The console is in great condition. Pokémon Blue is working, however, Pokémon Yellow and Gold both do not appear to hold their save games which apparently means they need new batteries. Someone might be able to figure out another fix though. All other games work fine. All 6 games are guaranteed genuine, having been purchased upon first release in the early 2000s. The battery pack works when it’s plugged in, however I haven’t tested the charge of it so cannot confirm that it will hold charge without being connected to mains.
eBay