Krys G.
Yelp
This is a great place to spend a couple of hours with your kids, whether you're locals or visiting Santa Fe. The place features a full body-size thing where you can press your body into little pins and it makes the impression on the other side. I know it sounds insane, but check out the photos posted, and you'll get what I mean.
There's also freewheeling with magnets, bubbles, drawing, playing in fountains and water, face painting, a rock climbing wall, a place to bake stuff and a quiet corner for reading. There's also a full outdoor area with plants to explore, a working well and pulleys and a water wheel and a full greenhouse with earthworms and other fun stuff.
It appeals to a wide range of ages too, since my son is 3, and there were definitely some older kids there too. He had a fantastic time and was able to learn some stuff too. It's a complete free-for-all and unstructured, so plan to do a bit of running around if you're with a young one. I didn't feel like the place was particularly cordoned off or supervised if you have a child wander off (know what I mean? gotta keep an eye out.)
Admission for kids over 3 and adults is $8 ($4 for NM residents, $1 on Sundays,) which seems steep, but my husband read that it doesn't even come near helping them cover overhead costs, so they encourage donations. They are closed Mondays and Tuesdays, except during the summer June-Aug. where they're open Tuesdays.
Definitely a great place to hit if you're in town with your kids, have dragged them all over Santa Fe to museums that have nothing to do with them (say...Georgia O'Keeffe?) and are looking to do something that's completely kid-oriented.