From 5 to 2 points

* The holding rods are too unstable. Since the ball rail is usually by the bending under tension, it warps by the other on this rod hanging rails.
* Manual too complex. For the 4-way loop I would have needed an extra 2 hours even 3 loops were to build only with a lot of sensitivity.
* Rolls a ball too quickly in the worm, located ball fall out therein.

Conclusion:

* The above points lead to lasting the balls fall out what the fun extremely decreases.
* Instability of the overall model produces permanently the need for readjustment.
* With a little simple-held sample model, I would have given 4 points! The overly complex sample model corrupts a lot of fun, both in the construction and afterwards!