Review from IMDB:
Early in his career, Tinto Brass tried his hands at a variety of genres. In the wake of A Fistful of Dollars the Western was hot in Italy and so even TB had a go at it. The resulting film is definitely watchable, and with interesting cinematography and decent acting it is much better than many of the other low budget atrocities Cinecitta would throw at the unsuspecting cinema-going public in the following years.
Amongst the elements one could criticise is the wiseness of the casting choices. Both Philippe Leroy and Adolfo Celi are fine actors, but they do not blend very well into this setting. Leroy is not enigmatic enough for his role (he also looks uncomfortable in his gear) and Celi is better at playing non-physical villains.
The film has little to add to the genre. The title hero, Yankee, is just a slight variant of the man with no name and throughout I watched this with a sense of deja vu. Brass certainly had a good look at the work of Leone and Corbucci. In turn, Sergio Corbucci seems to have watched this – the final scene appears to be the inspiration for Corbucci’s I Crudeli.