This game has a tad different layout compared to other VB-games, and here's why: at the back of the box it says "NINNTENNDO"! Ok it can happen!?! BUT the cartridge EVEN says "ninntenndo"!! Hmm ... how about the game itself?
Once you turn the VB on you'll land at the main screen (after the regular precaution warning, vb-offset, and auto-pause) ... there is NO intro!!
The game has pieces of worm (. er, pipe) falling from the top of the screen, the gamer is supposed to close off all connecting pipes in the playfield, while rotating & shifting the pieces that fall to the bottom, a pipe will disappear when a top is closed off and/or when it touches a side or bottom wall.
The first few levels are quite easy, the latter levels (the levels differ in difficulty each time you play the game, even if you choose the same difficulty level). The levels then get really spicy: sometimes you are forced to use tricks and skills, like when you seal a pipe that has at least 10 pieces (read: worms) in total connected, that gives you a Bonus Angel (whom is summoned by the Manga-style Lady who stands at the side of the screen 'cheering' at your success). The Angel then chops away the entire bottom layer of the playfield with an axe!!
Oh my! BRUAL VB VIOLENCE GALORE!!
You can understand from this that the game get's quite tense at times, but then you're rewarded with a happy winning-theme music, after the screen tells you to "take a rest!" and the game gives you a worthless password which you can't insert into the game (?!?), then you're on to the next level.
About the so-called passwords, they are not really passwords, because even they are different each time you start playing a new game and finish a level. So if you were to lose your memory, say, while resting, you couldn't put the password in!!
Also note a tiny glitch if you put the game on pause, the level-overview will standard disappear, however when you press (and keep pressing) the A button you can sneakely see the level-overview, this will come in handy when you need to buy yourself some time.
In short: The game is a Tetris clone! Virtual Lab is like the Game Boy's/NES' "Pipe Dream". It has it's faults, but sticks to a simple and easy-to-use formula. The only 3D effect you'll see in the game is the different layers in the front/back-ground. The in-game music is all the same. You like this game or you don't.
My opinion: I think it's ok. The game is really simple to play, yet nifty in the way it makes you think about how to solve/finish a level, it's like V-Tetris but slightly more basic, too bad the producers never thoroughly finished the game.