I have a multi game cart for Game Boy which has Pokemon Diamond/Jade (the Sonic bootleg version), Super Pikachu Land (Super Mario Land hack) and I believe it had some others too... But I can't find the cart anywhere.
The Pikachu Land was my favorite, I actually beat it once when I was a kid and it was hard. o_o Scrambled control over the character, everything felt slippery. But it was really good!