Humble Hero: Very much so. So much so that he refused to take command of the Autobots when everyone else around him knew he would be the perfect choice for the job. And only accepts when he is left with no other choice but to assume command .
The Leader: Type IV; he leads by example and by being one of the most levelheaded, sensible, and honorable of the Autobots gaining their respect and undying loyalty through his sheer strength of will, determination and genuine love and care for his comrades.
Nerves of Steel: No matter how dangerous or dire the situation. No matter how grim things may look, he never loses his cool and always remains calm and levelheaded.
Nice Guy: He wouldn't be Optimus Prime if he wasn't this.
Hero Antagonist: Unlike Zeta Prime, Omega proves an actual heroic character, the boss fight with him has him making comments to keep fighting in Iacon's defense. So he would be cool to have as an ally, but most of his screen time is in the Decepticon campaign.
Leader of the Decepticons, aimed at conquering Cybertron and doing what he views is returning the planet to its golden age. He's clearly out of his mind, stating that no cost is too high and he feels that anything that doesn't at least stay out of his way must die.
Determinator: Protest as to the otherwise absolutely suicidal nature of the current mission, he will roar for the course to be stayed. Even if it means ramming a frigate right into a space station, while he's on the bridge.
Deadpan Snarker: Breakdown seems to have a particular gift for bringing it out of him.
Megatron: Into the tunnels, Decepticons, and try not to get crushed by the trains.
Villainous Valor: One of the main reason the Decepticons are loyal to him despite being a Bad Boss, he's not afraid to do anything he'd order them to do himself, probably part of why his men running from a fight ticks him off so much.
Wrong Genre Savvy: Assumes that key Zeta Prime was holding the Iacon vault was the Omega Key. Turns out it was just a signal to activate the real one, Omega Supreme.