6.5 on their scale is “okay” and if it had single-cartridge play it was something I was seriously considering as it would add a lot of fun to our home 3DS library.
Unfortunately, my hopes were dashed when one of the hosts of the podcast responded to my tweet:
@flameflash Multiplayer in Mario Tennis Open is both online and local. Single cart play is not supported.—
Aminka (@GameOnAminka) May 18, 2012
At least we still have Mario Kart 7 freshly patched and ready to race online or locally with only one cartridge.