No, nay, never! They're a waste of time, for several reasons:
1. There are almost ALWAYS roller coasters/other impressive rides to be ridden and credits to be earned.
2. The games are almost always rigged so it's nigh on impossible to win.
3. If you DO win, what do you do with the prize? Especially if it's one of those giant stuffed things bigger than a small child.
4. They are quite often overpriced, especially after paying to get in and, more often than not, an inordinate amount of money for lunch.