In the grand history of Sonic the Hedgehog, there are endless characters, concepts, and pieces of lore for the film franchise to choose from. The first film stuck mostly to Sonic and his iconic nemesis, but the new sequel seems to be taking a very different direction with Dr. Ivo "Eggman" Robotnik.
Many of the mainstays of the Sonic the Hedgehog franchise have evolved, changed, or been completely rewritten over the years. Eggman is in the unique camp of characters that have barely changed because he always gravitates back to the hilarious antagonist he was from the beginning.
The announcement of the Sonic the Hedgehog movie came with a tidal wave of excitement from fans of all ages. Of course, most of the conversation was dominated by the terrible initial design of Sonic, but even in those dark times, fans were still enticed by the prospect of Jim Carrey as Dr. Robotnik. The iconic star behind some of the most animated performances in all the comedic cinema was an inspired choice for Robotnik and was immediately thrilling for most. He wound up not looking much like the classic Eggman fans know and love, but excitement still remained. When the film launched, Sonic was fixed and immediately beloved. Unfortunately, though Carrey's performance was excellent as expected, the film's take on Robotnik was missing a lot of the spark from the original source material.
Carrey's take on Eggman in the first film was an arrogant, angry, self-centered, scientist who works for the U.S. government. He berates his military handlers and his personal assistant Agent Stone. He becomes swiftly obsessed with Sonic, both because the hedgehog's immense power can be used for evil science and because Robotnik's ego demands he destroy all who challenge him. His robots are somewhat inspired by semi-grounded military drones. He makes references to his work with very real military units like the Shadow Wolves.
Bragging is very central to his character, but he comes across as mean before anything else. He's constantly trying to best his nemesis, but he's also always in competition with whoever happens to be standing around nearby. Perhaps most strangely, the film's Robotnik constantly keeps up with Sonic's barbs and jokes. He's in control, yet constantly fighting for recognition. He's occasionally funny, but in the same way as Sonic. The film's Eggman is definitely a fun and identifiable character, but he isn't quite the character he was in the games.
The biggest aspect of Dr. Eggman that has been central to his character since the beginning is the perfect balance of intimidation and piteousness. In the early games, he pilots the giant threatening robots until the moment Sonic destroys them, then he runs away frantically. In the more recent games, he is the most common face amongst Sonic's rotating cast of bad guys.
There's almost always a bigger threat for the blue blur to battle. From Shadow the Hedgehog to Chaos, to multiple versions of Metal Sonic, there is almost always a bigger threat on the horizon. This has forced Eggman onto the same side as Sonic from time to time. Working with others despite a strong desire to be considered the best is a classic Eggman trait. Though he has no significant superpowers, he has an almost unnatural ability to manage tenuous alliances with powers far beyond his capabilities. Whether it's some incomprehensible monster or his own worst nemesis, Eggman knows how to get what he wants from others.
In-game Eggman is a braggart, and he treats his many underlings with disrespect, but his massive insecurity is the linchpin of those traits. In his newest appearances, like the Sonic Boom franchise, his connection to Sonic is partially on purpose. He sees Sonic as his nemesis and feels a sense of mutual respect, even through all the insults and violence.
Eggman is a unique character in that his villainy is largely performed for its own sake. He wants acclaim, success, dominance, but above all else, he wants to beat Sonic. He's a man of incredible intelligence and absolutely no emotional self-awareness. He's the perfect foil to Sonic the Hedgehog, whose primary character trait is a 90s sense of general coolness. Game-only fans know next to nothing about Eggman's backstory because it isn't necessary. The first film's take on the character is more akin to a classic bullied nerd trope, but even in his brief appearances in the trailers, it's clear that the second film has adjusted the character.
It's obvious that Sonic 2's portrayal of the character looks more like the source, but he acts more like him too. After his time away, Eggman returns with a targeted hatred of Sonic and a specific new view of their nemesis relationship. He's teamed up with Knuckles, showing off his famous team-building ability. His robots have begun to take on a more cartoonish appearance, much more aligned with the game's imagery. The massive robot briefly depicted heavily resembles Eggman's many self-designed creations. Sonic the Hedgehog 2 seems to have found the correct direction for this iconic character.