Snap circuits are neat - but I'm not a huge fan. They are generally fairly very "high level, complex" building blocks. Even most of the definitions of what the pins (of the modules) do aren't described, nor referenced in any instructional way.
I agree 100%. I had exactly the same disappointment when my son started playing with Snap Circuits. It doesn't really try to teach any concepts, and the manual is is written like a boring lab textbook ("OBJECTIVE: To show how a resistor and LED are wired to emit light") and not at all geared towards creativity or exploration.