I think the other comment here is quite unfair to this movie. This is not supposed to be serious, this is not supposed to be a real movie. This was just a joke a few friends made with their own camcorders. Just by accident, someone on a Portuguese channel (Sic Radical) found out about this, and decided to air it. The cult was then born.
You can't actually say the special effects are bad, as there aren't any. The mysterious cloud of smoke that appears when the master ninja comes up is so obviously a pack of flour thrown from a nearby tree - you can actually see the package falling as well... the "evil robots" are the same guys inside card boxes...
the script is bad? well, if there would be a script, it would be bad, yes... but as far as i know, there was no script at all! This is just the kind of movie we all wished we could do back when we were kids, with our friends, just for the fun. It cannot be taken seriously, as it isn't a "real movie".
Still, for those who can find it, see it. Only in Portuguese, but a few laughters are guaranteed for sure!