I havent tried writing a game review before, so forgive this for being terrible! I don't want to give review scores, and in general would prefer to focus on the positives of a game. This game will be an exception to how I'd like to write these in the future.
It's hard to review this title without focusing on its negatives and comparing the games to other games, so before I get too far into the negatives of it, let me preface this by saying that I like this game.
It's split into 5 sports (soccer, tennis, golf, baseball and horseracing) with an additional amiibo game and a horse care game built into it.
Generally speaking all of the games are fairly mediocre, cut down versions of more fleshed out games. I expected this going in, so didn't mind. Given that you're getting five games in the one package at a fairly low price (I paid AU$49), it's not too bad at all. I feel that the games themselves are fairly lacking in content, there are only four golf courses, for example.
All of the games (save horse racing) are a series of three knockout tournament cups and a freeplay mode.
The first sport I tried was tennis. It controls well and I like it. You hit the ball back with a standard strike or, if there is a coloured circle on the ground, run to the circle and press the corresponding button for that shot type. Or press your cheat button, X, which automatically acts like it's the right button. Why would you press anything other than X, then? I'm not sure. Perhaps it's disabled in multiplayer. Mario Tennis Open is also on the 3DS, and is probably a better game, but if you're just after a simple tennis fix then this is pretty solid.
Next up was soccer. I had a little bit of difficulty with the controls in this game, but still found it not too bad. The soccer game is actually very balanced and fairly hard to fault. Occasionally the ball will have a rainbow flashing effect, meaning that anyone can do a special shot with it. This mainly serves to intensify the game a couple of times if the other team has possession of the ball. While playing it, I found myself wishing I were playing Mario Strikers Charged Football instead, but this is a lot easier than finding all of my Wii stuff. This is a much simpler game, which isn't necessarily a bad thing.
Each golf game is played as 1v1 competition. The controls are fairly standard for a golf game. There's not really much else that needs to be said about this. It does the job of a golf game well, but if you're after a more 'complete' golf experience with more courses, etc, Mario Golf: World Tour is also on 3DS. I prefer Mario Gold for course variation and more game modes (including a standard golf game mode...).
I didn't particularly enjoy the baseball game. When batting, you have a red box with yellow sides. You can move the box horizontally with the analogue stick. If the ball is in the red area, you press A. If it's in the yellow, you press B. I found it really difficult to work out where the ball would be to actually hit it. Pitching was okay, though there wasn't really a lot to it. You select a type of throw and press A when the indicator is in the right spot. That's pretty much all there is to it. Field-work is handled automatically, which is nice. In the game, you have a couple of special moves that you can use. These feel completely pointless while pitching as it's just a normal throw. They're nice when batting, as you don't need to worry about hitting the ball with the right button or in the right spot.
Horse racing is fairly enjoyable. For starters, it's the only game that isn't a knockout tournament. Each of the three cups is a series of four races and scored similar to Mario Kart. Racing itself is fairly slow. There is a carrot bar, which allows you to push your horse a small amount and a star bar, which gives you a turbo boost. There is also a slipstream effect making it better to stay in a pack rather than racing off ahead. So racing is a little bit technical, but easily managable given the slow racing speed. There is also an area to bond with your horse, involving petting, brushing and a free walk around a paddock.
The game also introduces a new series of Amiibo cards. There is another game which uses amiibo cards. The game comes with one in the box, but it seems like the amiibo game requires three amiibo cards. So why not give three of them? I haven't had a chance to play the amiibo game just yet, so I can't really talk about it. I bought 6 packs of amiibo cards and only got a single duplicate card, which is pretty lucky. I don't know if the game is going to hold my attention long enough for me to want to get the whole collection of cards.