How to say 'hide-and-seek' in Spanish?
I used to say: "Vamos a jugar a las escondidillas.
Also escondidas and escondis but the first one was more common.
Here's a link from our very own site on tag I found quite interesting, especially since it goes by so many different names in various countries/regions:
Esteban, to answer your "puzzle" question, I would say:
Armar un rompecabezas = to put together a puzzle
I have heard "hacer un puzle" ('puzle', con una z, viene en el DRAE) but I prefer the former.