I only played it briefly with a friend (street fighter) and the actual 3d seemed neat but it didn't wow me (or my eyes couldn't focus properly?).
I wanted to be wow-ed at the level of that old cowboy arcade hologram game. :)
I'm sure since it was the newest hardware it was the best.
The biggest reason the 3DS can't provide what feels like a hologram is that the screen is too small. As objects come closer, they need to get bigger, but they can't get bigger than the screen's dimensions. So most games focused on objects going into the screen, instead of popping out.
But I think the 3D served one really wonderful purpose: it made the small screen feel larger overall. Not large, maybe, but larger than it really was.
> old cowboy arcade hologram game
Sega Time Traveler
Playe it a few times. Never made it very far. Sure was cool to look at though.