Very nostalgic game. It is build like a Nintendo Game boy, nice to hold in the hand. It contains 400 games (or versions of games, as there are many similar ersions of Donkey Kong, Mario etc) and these are a really good selection. There really is something for everyone. It charges via USB so good as you don't need to keep buying batteries. You can add the controller and have a second player on some games. It can also be plugged into a TV. If you are doing this, the quality is OK, much like the quality of an 80s computer like a ZX Spectrum or C64. However, the supplied lead is very short. If you plan to play on a TV, get extension cords.
Overall, very happy with this. Lots of nostalgic fun.