Main attraction/star player in Fountain Hills here, Yelpers. Obviously, one can assume by the name that there is a "park" and also a "fountain" in store when they visit for the first time.
The fountain does erupt like Old Faithful at timed intervals (every hour?) and is pretty cool and makes our town unique. Please take extra precaution on windy days, as fountain spray WILL blow on pedestrians on the sidewalk. Also note that a lot of ducks reside in the water... ;)
The park is well-maintained with tons of grass (which is rare in AZ) as well as a few businesses at the south end. It is canine-friendly which makes my heart happy and I'm sure puppies feel that going here is a huge social affair in their doggy world. The park also has a mini amphitheater on NW corner for outdoor concerts/speakers, etc which is rad and was pretty well-planned.
They also have a kids water play park thing-y in SE corner for them to frolick and splash around. And, they even have a memorial area (not sure for what - sorry!) on the east side too.
So, this park is pretty much "the tits" and I'm rather proud of it being in our town. I've gone here to walk solo when I needed some fresh air/exercise, vent with girlfriends about men and flap our gums about other girlie stuff, have been on dates here (both were crappy), attended Norooz (Persian New Year) and had picnic w/my Persian bestie and her family, and just... people watched sitting on a bench!