Lets do this Preview as a flowchart!

Q.Have you played Mario Tennis: Open on the 3DS?

Yes -> It's like that in 3D with the added bonus of Mega Mushrooms, that make you bigger for around 3 points, you're moves are heavier and your shots hit right to the back of the court lobbing anyone who thinks they can defend them from standing on the baseline.

No -> What is wrong with you!?  It's a Camelot made Mario sports title! These things are the absolute best. They seem simplistic at first but underneath all the Mario veneer is some deep gameplay that takes minutes to learn and hours to master.

Would you like to know more about the games modes and returning features?

Yes -> I appreciate the enthusiasm but the demo I played was only a 1V1 Mario Vs Bowser 3 game affair.  all the controls are the same from the 3DS version so if you have those memorised you'll feel right at home. Here's hoping for some robust online features, costumes and hopefully a decent single player experience as they've been lacking in Camelot's recent Mario sports titles.

No-> Well I'm not going to tell you anyway ;-P

Mario Tennis Ultra Smash seems almost identical to Mario Tennis Open on the 3DS, but I don't think thats really such a bad thing. I look forward to taking on all comers later this year.