In Hardware

Check this out... an NES Homebrew game called NeSnake. It' pretty much like the regular game Snake, like you would play on a cell phone and such. It has all these cool Hooks to it though. VERY well made game. It feels like it was an original release because it's so solid.

Get more info + download the game itself from here:

Yea between the 25 levels the music and the in game instructions you would expect to see the Nintendo seal on that game. It was very well completed.

I gave it a go and really liked it. There were certainly a lot of official games that were worse than this.