I loved it, though i personally never owned one. I played my friends and it was so cool, it reminded me of those little games you'd get as a prize in a child's meal from fast food restaurants.
Example, I had gotten a Sonic the Hedgehog game from Sonic the restaurant. It booted like a gba game with a title and theme, and a new game/ continue option. And you would race around collecting rings.
I think that's,why it was so big except you'd get to play actual games.