As the origin story of the beloved hero, this is the film that gives us the basic idea of what Iron Man is at his core.
Without Jon Favreau’s Iron Man, there would be no Tony Stark, and this is the film that offered up the armored Avenger in his crudest and most rudimentary form.
To accomplish that, the film shows us the Mk. 1 armor during Tony’s imprisonment, which is a bulky walking tank that’s mostly used for melee combat but also features some rockets and flamethrowers, plus whatever other weapons he could jerry-rig during his time in the cave.