Mario Tennis Open is a bit uneven, but remains an enjoyable game enhanced by its customization and mini games.
The annoying power shots from Mario Power Tennis are gone, replaced by chance spots. These are the same from the N64 version, except now you get chance shots for lobs and soft serves. Hitting one of these spots while pushing the correct button makes your shot more powerful (shot could be faster, higher, softer, or even curve at an amazing rate). These make the game a riot at first, but then you realize lining up to these eliminates any skill. The original N64 version worked perfectly because you actually had to skillfully get the shot past your opponent. No such case here.
Even so, Mario Tennis Open remains fun. Why? Because the control scheme is awesome, and the matches, though based less on skill, are intense. There's two styles of controls. You can use the touchscreen or the buttons. I prefer the buttons, but I would occasionally use the touch screen to control my chance shots. Like the original on the N64, your player's stats vary, but surprisingly not as much. I really enjoyed unlocking Metal Mario (my favorite character in the game) with a secret code, but the other ones are awful (different colored Yoshi's?!!!). The tournament mode is awesome, and you get 8 championships to play in. The stages themselves are standard Mario like courts, ranging from the sandy courts of the desert, Bowser's Castle (actually a court, not a mini game), and an icy court. The second variation of the Galaxy Arena court actually changes its shape depending on what shot you use. All these are quite good, though not as much fun to play on as the ones in the N64 version. You can also get another camera mode by holding the 3DS closer to you (from right behind Mario), but it's useless because it moves for you, and the 3D effect is turned OFF (worst idea ever, Nintendo).
Mario Tennis Open get's bonus points for its customization (unlocking all the stuff is freaking awesome) and mini games, primarily Super Mario Tennis. This game is highly original: combining tennis with the original NES classic. It's a hell of a lot of fun, and I prefer it to the actual game! The mini game with Luma is also awesome, because you have to hit on the squares that don't lead to the black hole, and take risks by collecting star pieces to get more points! Like I said, the customization feature (similar to Mario Kart 7) lets you buy extra gear from the store for your Mii (sorry, not for Mario, Luigi, Yoshi, etc.), enhancing the replay value.
The graphics look nice, but the 3D effect is terrible. I'm not sure what Nintendo was thinking, but there's barely any depth at all, and I could hardly tell the difference. It is tennis, but it would've been nice to have 3D that doesn't suck. It's the main feature for your handheld besides gameplay, and you choose not to use it? Nice one. The music is excellent, and even features a remixed song from Wario Land 3!!! Most of the sound effects are recycled from the Gamecube version (yawn).
Mario Tennis Open would be a huge letdown for me, but thanks to the customization mode and mini games, it's better than it should have been. Without it, I could've given this game at least a 7/10. It's a shame Nintendo seemed to not put any effort in the core gameplay. Still, the tournament mode is great fun, and the extra modes of gameplay breath new life into this 3DS title. Overall, an enjoyable trip.
Gameplay: 8/10 (Thanks to the extra gameplay modes)
Graphics: 8/10
Sound: 9/10
Value: 7/10
Final Score: 8.1/10 (B-)