touch_began obviously works, in the examples. Without posting an actual example of something that does not work the way you expect, we cannot possibly debug it for you! cvp speculates an indentation problem. I suspected it was being called but you were being fooled by it only printing out ']' (which is what i saw when i ran your touch_began in a minimal scene example).
if you are still having trouble, post a gist.
I would also recommend trying the logging code i posted, which not only will be easier to debug, but comes with a working touch_began.