Don't approach Taboo with just a question - approach it with an open mind as well.
That said, Taboo is one of the earliest "non-games" - that is, there is really no gameplay in the traditional sense of the word. You're asked for your name, age, and gender, and you're given some space to enter a question. Your cards are dealt, your fortune is revealed to you, you get some lucky numbers.
That's pretty much it. There is very little, if any, replay value, since even the most troubled individual lacks the patience to punch in question after question for hours on end. In addition, the grammar is poor in many spots...and don't even get me started about the "Time Machine on Nintendo!" bit.
Taboo is definitely a touch-and-go affair - but it's extremely captivating. Why so?
It could be our underlying curiosity, the human desire to know the future, or any number of deep-seated tendencies - that, or the game's artistic merit. The music and graphics are very well-done for the era, particularly the former, which is most definitely the high point of the game. Each of the cards in the major arcana has its own musical theme. Suspenseful, joyful, just downright scary - the score varies widely and is obviously designed to shake the player up a little. In addition to the music, each card in the Major Arcana and cards of different suits each have their own illustration, corresponding to the card shown.
This is astounding, and it can be creepy, too. The Hanged Man, blue in the face, drops down from the top of the screen without warning, suspended by one leg. On occasion, the sun on a card's back may morph into a skull, indicating a quite unfavorable card. The music for the some of the cards (e.g. the Devil) can be pretty jarring, too.
Don't approach Taboo with just a question - approach it with an open mind as well. The judgmental need not apply. Whether you think it's a force to be reckoned with, a load of bull, or just another slice of 80's cheese, just pop it in and try to enjoy it - I certainly did. If you can get past the corny introduction screen, you'll find Taboo to be a mildly entertaining diversion from the rest of the NES library.