I wanted to see a funny action movie ... I have chosen this one. Even if i hate Will Smith, I really enjoy this movie. I'll explain myself.
The storyline: Basic. Mad scientist who wants to control the world against an impulsive black cowboy who loves his guns and fists & an inventor marshall who creates some strange stuff to solve problems without violence. Of course they are helped by a kind of "sexy girl" in order to satisfy the audience.
The characters: Originals (except Salma Hayek).The couple Will Smith/ Kevin Kline (bad boy vs gentleman) is great! It works and it's not boring. They are totally opposed so good rythm and fun... The bad scientist (awesome Kenneth Branagh) is hilarous (ass bowl, strange beard, crazy look). You can find him too exuberant but this is the character! Fight scenes are composed by interesting ideas (disguises, ropes, train with gizmos...). The dialogs are quick and sharp. Never the time to breathe in fact.
The landscape: An unique environnement. The scene takes place in an unexpected Wild West. Endless deserts, dilligences, horses ... and steampunk machines! It gives a Sci Fi feeling. The mechanical spider is a sucess! However sometimes the insertion of the characters is awful (bad special effects and chroma key).
To sum up, good movie. No master piece but not bad at all. If you want to have fun during 1h40 and not thinking too much, watch it!