Yup, like wdennie says. Jurassic Park came out in 1993, so your machine is now 23 years old. If you drive a car that old, you're likely to be tinkering fairly often. Bulb flickering somewhere in the dash of the car? Well give it a slap in the right place and it'll light up fine. For a while. But easier than taking it apart to replace the bulb or fix the dodgy socket. Radio a bit crackly? Give it a wiggle and it clears up. Most of the time.
Pinball is like that. Generally speaking it'll work, but there will always be things that could be adjusted/fixed/improved. And if anything stops working or you have questions, there are heaps of people on this forum that will help you get sorted.
Welcome!