In the "Transformers" film, the robots had more of an alien feel to them to fit the theme of an alien invasion. The robots (stated by Optimus Prime) in the film are actual sentient organisms and not just giant, mindless, and mechanical machines. The robots can also speak their own alien language sounding like what seems to be based on different pitches and frequencies. Alongside that, they gave them more alien features that probably wasn't mentioned in the comics or T.V. series such as a highly advanced exoskeleton, force field, and a special "alien meteoroid" mode which they transform into individually and arrive on earth in. The exoskeleton is a "self-regenerating metal" in which the aliens are composed of (stated in the film) that is the equivalent of living skin that heals itself.