The production met with about thirty different writers, and they all passed, as most of them felt that Iron Man was a relatively obscure character in the Marvel universe. They were also a bit nervous about working for an untried studio better known for producing comic books. Even the re-writes led to many refusals. See more

Goofs

When Tony reveals the power generation of the first arc reactor he uses in his chest, he gives it in gigajoules per second (more typically called gigawatts). Since the reactor is generating this much power, the amount of power available to the suit in the ending battle should not be dropping steadily, but should be constant until the reactor stops generating power. However, given the high amount of advanced technology all constantly being run at the same time while the suit is operational, it's entirely plausible that the suit is using more energy per second than the reactor is generating (i.e. JARVIS' comment that the Mark I chestpiece was not designed for *sustained* flight), resulting in a steady loss of total power available and causing him to switch to the backup power source while the reactor catches back up. See more