Apparently it's the most difficult Mario Tennis game ever, but it also brings the first story mode to a Mario Tennis game since the GBA title Mario Tennis: Power Tour. (gamesradar.com)
The newly announced Mario Tennis Aces is delivering the first story mode for the series since it was on Game Boy Advance and will arrive this Spring. (shacknews.com)
«And this time the game adds the first story mode since the Mario Tennis game on Game Boy Advance, offering a new flavour of tennis gameplay, with a variety of missions, boss battles and more.» (vg247.com)