A particular shocking aspect of this movie's badness has to come from the poor audio quality. Generally Italian movies shot with no direct sound aside from a scratch "dirty track" from which to guide the dubbing loopers in post production. This film doesn't seem to have any dubbing at all, at least not obviously. It also features a lot of actors flubbing their lines and scenes (like when we first meet Silva) where we can barely hear anything. It leads me to believe the filmmakers thought to make this "the American way" and save money in post production by attempting to make the scratch track useable. Fabrizio probably didn't have the money to get Borgnine, Napier, Balsam, all the NFL players, etc. to come back to Rome and dub themselves, so instead opted to just try and get it all useable while filming as a cost-cutting measure. Unfortunately, Italian crews just weren't used to working like this and it led to sub-par results. Still, it's interesting from a B-film historian perspective.