Nearly 15 after its release, I get to try a Virtual Boy that's actually working, with a proper visor and near proper stand. I wasn't expecting much, between awful hearsay and the fact that most 3D effects don't seem to work on me. So maybe this review is a product of low expectations.
But honestly, I was pleasantly surprised. I didn't find the setup uncomfortable or hard to look at, and when you took 15 seconds to adjust the settings the 3D effect is really powerful, and did add enough "depth" to tennis to make for something I'd pick up and play again. Sorry, the pun was necessary.
When it gets down to it, I like the fact that the 3D really does contribute to the gameplay. The sounds with the little speakers next to your head were better than decent, since it creates a neat stereo separation. It doesn't take much time to queue up a couple of characters and play for a bit, then put it down, which is frankly something I look for in a retro game. I also rather like that is decent latitude for moving around and making shots. I think it plays pretty well for a simple title.
There are a decent number of characters with their own attributes. They do show a little emotion when they succeed or fail. The character graphics are flat looking but that's fine. Even the shades of red get come across with enough texture to represent the images well.
But really this is as much of a judgement on the Virtual Boy itself. I also had a go with Red Alarm, but not enough of a go since I didn't have the instructions, and kept running out of fuel. I somehow think the two are related. But the vectors, 3D navigation and stereo sound came across even more powerfully, so I'm really looking to spending more time with this game. The only early fault I found was clearly a limit on the VB's power, that the depth of view the game could display is pretty limited.
It would be hard to recommend a Virtual Boy to a casual retro gamer, because they cost so much and have such a limited library. On the other hand, they have a definite wow, uniqueness factor. And if you already have one, Mario's Tennis is cheap, definitely worth a pickup.