The first post-'Avengers' Marvel film is more fun than 'Iron Man 2,' but suffers from underdeveloped villains and potholes that prevent 'Iron Man 3' from gaining a fun amount of traction.
In short: the events of 'The Avengers' have traumatized Tony Stark/Iron Man, who has become completely focused on building new suits in preparation for threats that may be more than his genius level intellect can overcome. Meanwhile a dangerous terrorist known only as The Mandarin sets his sights on Stark and the US president.
Tony Stark is the most interesting aspect of 'Iron Man 3.' In the past films, he's a very public and cocky genius who believed nothing can stop him - but '3' opens with a reclusive Stark working tirelessly to prepare for threats he never imagined prior to 'The Avengers.' The third 'Iron Man' film alludes to the 'Avengers' events as world changing - Stark now lives in a world of aliens, gods and monsters.
But beneath Stark's focus and preparation is the trauma of having almost died in the finale of 'The Avengers.' He now suffers from panic attacks and refuses to discuss New York, aliens or the Avengers themselves.
To move Stark forward, 'Iron Man 3' smartly returns Stark to his roots as 'the mechanic.' For all his wealth, power and even the Iron Man armor, Tony Stark's superpower is his incredible intellect. This film establishes that he is not merely a 'man in a can,' but a genius intellect who turns a shopping trip to the hardware store into a dangerous arsenal of weapons.
The past Marvel movies have equipped Stark with increasingly more refined, dangerous upgraded versions of his iconic Iron Man armor- but for much of 'Iron Man 3,' Stark must stop a global terrorist with only an ill-equipped prototype armor with none of the usual bells and whistles. One great sequence has Stark fighting enemies off while only wearing pieces of his armor: one glove and one boot.
This gets to the great creativity of 'Iron Man 3,' both in how Stark must creatively fight and how he can use his tech. Past movies reveal the clunky process of getting in-and-out of the Iron Man armor: Stark usually has to stand still while machines remove the suit piece by piece. In 'Iron Man 3,' Stark can jump directly from one armor into another and summon the suit with just a wave of his hand. He can now suit up while running. This may sound trivial, but it allows the film's creative team to find fun/exciting new ways for Stark to fight as Iron Man.
One of the strongest aspects of 'Iron Man 3' is its sharp dialogue. Director Shane Black also co-wrote the screenplay, which is saturated with his trademark wit and style (see 'Kiss Kiss, Bang Bang' or 'Lethal Weapon' as evidence). The verbal back-and-forth between characters is almost never boring.
But 'Iron Man 3' is not without its flaws, of which it has many.
The film's momentum shifts jarringly from slow to overdrive at times. This is mostly because the script is filled with funny, but momentum-killing scenes. Several scenes - including Stark discussing potato guns and engaging an overenthusiastic superfan - could have been rewritten, cut down or cut completely. This would have cut the pace-killing fat and created a more streamlined ride of a film. Instead, 'Iron Man 3' feels tedious at times - never to the point of being boring, but enough to kill the film's exciting tone.
Some peripheral characters and actors are wasted. Maya Hansen (Rebecca Hall), Iron Patriot (Don Cheadle) and even the Mandarin (Ben Kingsley) are pawns who simply fulfill plot points. They never feel like humans- they're limited to one-dimensional roles. This is bad because Hansen is critical to the very core of the film and Mandarin never feels as dangerous as a supervillian deserves.
If there's one flaw with the Marvel films, its that some incredibly important plot elements are left very ambiguous. In 'Iron Man 3,' it's the abilities of 'Extremis,' Maya Hansen's research into hacking human DNA. Throughout the film, Stark has to fight Extremis-powered soldiers, who enjoy unclear new superpowers, including super strength and even fire breathing. Not to sound like a stickler, but not establishing rules or limits for the Extremis abilities is lazy and annoying. The villains always have just the right Extremis superpower needed in that moment. And the writers know how invaluable defining a characters powers/limits are because they go to great length to establish just what Stark and his suits are capable of. We know when Tony's suit doesn't have enough power to fly or fire Repulsor beams, but little to no effort is made to define Extremis, other than to say it makes a normal human more than able to fight an Iron Man armor toe-to-toe.
'Iron Man 3' succeeds in evolving Tony Stark as a character, but only manages a fair job of constructing a meaningful or exciting plot.
In short: see the third 'Iron Man' film on the big screen, but don't go in expecting anything as fun as 'The Avengers' or awesome as the original 'Iron Man.'