Carl Sandell’s review published on Letterboxd :
As lifeless as the first time I saw it, even if there is some pleasure in seeing characters that ended up sticking around. Seeing agent Coulson popping in trying to schedule a meeting means nothing on a first watch, which makes it cute now. That's hardly enough to make up for the lack of charm I get from Robert Downey Jr. The movie works hard to show what an exciting snarky bachelor he is, because it doesn't come naturally. This could be more on Jon Favreau's uninspired filmmaking than the actor, and I don't understand the producer that paired the two.
It's a fancy piece of CGI-wizardry though. The Iron Man flights and fights look very pretty while still staying in some sort of reality, despite the blue energy beam into the sky at the end. The attempts at reality are a bit rough in the beginning though. It constantly recalls real horrible footage of war and terror in the Middle East, which is a well that has run very dry by now. It's no longer fodder for cheery action movies and this one really has no interest in anything other than using it as a trope to build a superhero in the most shallow way.
As such it's still of note that the eye-opening clash with his own weaponry leads Tony Stark to build new weapons that he alone can control rather than actually becoming more of a pacifist. Guns and violence are the only tools in his frame of reference because of his heritage, which sets him up for further disappointment later on when his epiphanies turn out to lead him in a circle. This could be pointed if the filmmakers seemed to care about more than making billions off a franchise.