I have it - the deluxe box set one -- you get the unit and IJ game (a TRU exclusive)...
It is fun - reminds me of the old Sega Game Gear handheld. Game is fun -- and educational. When you reach certain point on each level you have to answer a bunch of math questions to be able to continue on.
I played it for a few days -- and now it's back in the box and in the musem (where it belongs)