Much like how Desperado was a weak follow-up to El Mariachi, Once Upon a Time in Mexico continues the trend of being a mediocre action film that pales in comparison to the hilarious film that kickstarted this trilogy of films.
The most glaring issue with this film is the sheer amount of things that are taking place. El Mariachi was a simple case of mistaken identity that culminated in a crime story. Desperado was a revenge story that, while messy in terms of plot, still had a simple enough premise and a moderately satisfying conclusion. In Once Upon a Time in Mexico, the story is based around a presidential assassination the Mariachi happens to get himself wrapped up in... but there's also his own personal quest for revenge, [spoiler] yeah, he's lost another girlfriend, and this subplot feels incredibly forced into the film, [/spoiler] there's a plot in which **Johnny Depp** is trying to assassinate a character played by **Eva Mendes**, and the Mariachi has these two prat friends who are trying to rescue the president simply because of the reward in the end. The rest of the film is honestly too complex for me to explain, and it'll make your head spin - especially compared to El Mariachi and even Desperado.
The other main problem is that the Mariachi is barely in the film. The main story of the film really focuses on the politics centred around the assassination - with the real protagonist of the film being Sands, a CIA agent played by Johnny Depp. And to be fair to Depp, his performance is much more interesting than the portrayal of the Mariachi over the last two films. He's definitely the highlight of this film... but that's the problem. Mariachi is objectively the protagonist of the film, but he's also the one with the least control over the outcome of the plot, and that should never be the case with the main protagonist.
The film isn't all doom and gloom, however. As I said before, Johnny Depp is easily the best thing in the film, and he does give a pretty solid performance, as does **Willem Dafoe**. Even **Antonio Banderas**, despite (or perhaps because of) having less screentime, gives an improved performance as the Mariachi. In fairness, I don't have too much to criticise in terms of acting for this film - it's all reasonably decent and while not outstanding, it does the job.
The action is also fun, minus one town shootout with abysmal shaky-cam and rapid editing. The following motorbike chase is enjoyable, and there's a very fun gore effect towards the end of the film that honestly caught me off guard a bit. There are things to appreciate in this film, but it's unfortunately a little bit clustered for its own good.
Overall, I'd consider El Mariachi to be the undisputed best film in the Mexico trilogy, with Desperado and Once Upon a Time in Mexico being on roughly the same level - although choosing between the two latter films, I'd go with Desperado purely for being less clustered and more enjoyable.

**Tons of stylish action, a big budget, a script reduced to the minimum and a huge list of actors with nothing to do.**

It was only when I saw this film that I realized that it is the last film in a trilogy that begins with “Mariachi”. However, I saw it after having seen “Desperado” and that allowed me to have a better understanding of the story: the gunman and his girlfriend are chased by a drug dealer until the day his men manages to kill the girl. Devastated, the Mariachi retires to live out his days in bitterness. After a while, he is called by a CIA agent, who gives him the opportunity to take revenge while preventing the total success of a military coup that will assassinate the Mexican president.

Sound confusing? Maybe because it is! The script is very light, without beauty, care for details or stylistic refinement, and the text ends up being dominated by what I defined, sarcastically, as “latinxploitation” when I wrote for “Desperado”: a bunch of cheap stereotypes about Latinos and Mexicans. And I continue to have the feeling that these films are not healthful to clear up these preconceived ideas that dance in the heads of white, Anglo-Saxon, English-speaking America.

If we saw director Robert Rodríguez dazzled by action scenes in “Desperado”, here he lost his mind: there are enough bullets for another invasion of Iraq. For those who live far away, Mexico may seem like a highly corrupt country and the difficulties that the authorities face in the fight against well-armed, cruel cartels with strong allies abroad are very well known. The film, however, takes two steps further and transforms Mexico into a land without law or ruler, where the order comes from those with bigger weapons and their hands deep in cocaine. Perhaps for this reason, the film did not have much support from the Mexican authorities and ended up not even showing the Mexican flag which, in the film's presidential palace, is replaced by something else with stars. I am still unable to fully understand this flag exchange. Speaking of action, was I the only one who smelled a faint whiff of Tarantino in this film's action scenes?

Of course, with all this, the film develops and evolves very quickly, and we don't have any dead or boring moments. From an entertainment point of view, the film works very well, considering that we are an audience that seeks action and doesn't mind turning off our brains and accepting what is given to us. The underlying problem is that, if the script is already weak, things get worse if it speeds up like this. After a point, it no longer matters who is trying to do what. They're all shooting. For what reason? Maybe they don't even know!

Despite the poverty of the material given to him and the poor construction of his character, António Banderas continues to deserve our attention, even if, in this film, it is unquestionably Depp who stands out when we talk about the cast. There aren't many actors capable of shining in an underwritten character, but he does it and steals the spotlight whenever he appears, sending Banderas to the corner and turning Salma Hayek into an extra. Eva Mendes is sexy, but she has no material to work with, and Willem Dafoe is very weak. There are a lot of renowned actors and even a singer – Enrique Iglesias – in the cast list, which shows more desire to be in this project than the ability to add something good to the final product.