I've really been enjoying Mario Tennis: Aces on the Switch. It's my wife and I's new favorite game to play together. I bought it back at the beginning of October along with Super Mario Party (I'll get to that one later). And I was expecting it to take a back-seat to Super Mario Party. Man, was I so glad to be wrong.
It's interesting because it plays more like a fighting game than a sports/tennis game. But the back-and-forth nature of tennis stops the fighting-game nature of getting stomped by someone too good for you. The skill-ceiling here is somewhat high, but not too high, and the learning curve is very low. Players have access to a fighting-game-like power-meter that fills up as you do charge shots, make "nice" serves, and block opponents' special shots. When the opponent hits the ball back to you, most of the time, you will see a star appear on the court. If you stand within the star, you have access to two powerful options:
When your power meter is full, you have the option to unleash a powerful Super-Shot, which automatically hits the ball no matter where it is, lets you aim it, and can break the opponent's racket if not blocked correctly.
The opponent can try to tap the button at the right time to block the shot, or can use their power meter to slow down time to hit the ball at the right time more easily.
Yes, you can damage and break an opponent's racket. Normally you have 2 rackets for a match. Break both of them, and you lose the game! So be careful which super/zone shots you decide to try and return. It makes for a strategic decision every time someone wants to change the game with one of their special shots.
Yes, there is a medium-sized single-player story campaign where you go around a tennis-themed island overworld playing against opponents and doing challenges where you have to hit the ball in certain ways. Every level is creative in its own way, and offers the player a choice of whether to try and break the opponent's rackets or simply win the 2-set-2-game match. There are even boss battles, which, once completed, will unlock a special court to play in Free Play mode (the mode where you play with friends).
The skill ceiling is pretty low, but it does make for a good time, and has surprising depth.
If you're playing with someone of unequal skill, I encourage you to play doubles with intermediate AI-players. They mess up frequently, and that adds to the fun, and possibly allows the less-skilled player to get some points and possibly win a few games.