At a base level the game remains much the same, an arcade golf game with all our favourite characters from the world of Mario. But there are changes, too - some will think for the worse, but I believe they clean the game up and put the focus back on the golf itself.
Previously in Mario Golf, the "Career Mode" Castle Club served as a bit of an adventure playground with some RPG-like elements around a rudimental storyline. But in World Tour, Castle Club serves as no more than a 3D menu hub that you are free to run around and explore, buy items, customise your character and enter tournaments and challenges online and offline.
The other mode is Quick Round: choose a course, choose a character and play some golf. There are three 18-hole courses and seven 9-hole courses that need to be unlocked by completing challenges. But the game doesn't really explain how to unlock them. In fact, it doesn't explain much at all, which can be very frustrating.
But most importantly, Mario Golf World Tour is an excellent golf game. Using buttons or the touch screen, Nintendo has nailed the controls as well as the wind and terrain aspects. The main courses are standard golfing fare, but the additional courses are themed from familiar Mario environments. There is even an underwater course. That may sound preposterous, but this is Mario Golf, not Tiger Woods PGA Tour.