Uatu is featured in Marvel: Ultimate Alliance
The Watchers are among the oldest and most advanced beings in the cosmos. Eons ago, they sought to spread their knowledge to benefit the lesser races of the Universe. Their first attempt, on the planet Prosilicus, included sharing nuclear technology. When the Watchers returned to Prosilicus, they found the natives had all but destroyed themselves in a nuclear war. The Watchers blamed themselves for the catastrophe and vowed to never again meddle in the affairs of other races. Instead, they passively observe and record events for those who will come after the universe ends.
Uatu is the Watcher assigned to watch over Earth from his home in the Blue Area of the Moon. He is an altruist and has bent or violated his oath on numerous occasions in order to aid humanity. He revealed himself to the Fantastic Four when they discovered his home, telling them he would leave the Moon to observe humanity from a more distant area. He proceeded to violate his oath several more times to aid the Fantastic Four. He tried and failed, to prevent the Silver Surfer from bringing the planet-devourer Galactus to the Earth. For his continuous disregard for the Watchers' mission, Uatu is once placed on trial by the Watchers. He is found guilty but is released on his own recognizance. When the Shi'ar seek to prosecute Mister Fantastic for saving Galactus' life, Uatu serves as his lawyer and receives help from Odin, Eternity, and even Galactus himself to explain that Galactus is part of the universe's balance