5 stars for the exhibits
1 star for not controlling how many kids are there on field trips at one time.
Went today as a chaperone for my son's first grade class. Complete and total chaos.
I had a very small group of kids (3) that were trying to check out the exhibits and had a really hard time because there were at least 1,000 other kids there that were much older and so obnoxious. My 7 year old son was pushed, shoved, yelled at, had things ripped from his hands, cut in front of in a line, etc. Thankfully I was one of the parents that put their phone away and actually watched my group of kids like a hawk and was able to remedy the situations pretty quickly. There needs to be some control over how many kids and what ages are there at the same time for field trips. We couldn't even see some exhibits because they were so crowded and my little guys were no match for the much older kids that just sort of took over.
Go on a weekend or over the summer when there aren't field trips going on and you'll have a great time. Check out the planetarium as well.
Parking garage (Heritage Square) is $12 for the day or $5 if the AZ Science Center validates your parking ticket.