We love our builder buddy! I originally bought it to add height to our couches, but we end up using it for so much more. They make a great castle build, a balance beam and a structure to play other toys on (dinos, army, etc). I love that my 3 year old can move the pieces around independently and we can make it look all tidy at the end of our play.
I only wish that the blocks inside were available in a different colour than the cover.