The alien itself isn't officially named in the film, although some the comments on the YouTube video compare it to looking like a cross between Iron Man and a Yautja (especially as some of the sounds the alien makes are Predator sounds), while others compare the alien to looking like a Protoss.
Little of the alien's backstory is known, other then it's been tracked down by the US Military and has taken to hiding in a cornfield. The alien's existence is discovered by a young boy named Kyle, who doesn't see the creature but 'plays' with it by throwing a basketball into the field - which the alien in turn throws back.Kyle - who is living at his Grandparent's house with his older brother Jason following the death of their parents some time back - informs his older brother of his discovery. However, Jason is dismissive of there been something in the cornfield; telling Kyle that it's not normal for him to be spending all his time out in the fields, adding that their Grandparents are asking questions about it as well. Kyle, however, remains assertive and also denies that his actions are anything to do with their parent's death. Seeking to find out the truth, Jason accompanies Kyle to the cornfield with their dog Dodger - warning Kyle that if they get to the cornfield and there is nothing there then Kyle is doing the dishes for a week. Unaware to them, the military have located the alien and are moving in to destroy it.
Upon reaching the field, Kyle throws his basketball into the field in an attempt to prove that there is something there. However, the ball isn't thrown back and Jason eventually loses patience, telling Kyle that they're going back home. Suddenly, the ball is thrown back; regaining Jason's interest as he watches Kyle throw the ball back. This time, the ball is thrown back with incredible force, with Dodger barking and running into the field after picking up the alien's scent - despite Jason attempting to call him back. Dodger eventually runs back - whimpering but seemingly unharmed.The alien then reveals itself to the two boys as it walks out from the cornfield, easily towering above them both, before stopping in front of Kyle. Despite the potential danger, Kyle shows curiosity towards the alien, with the alien in turn looking at Kyle with curiosity. As Jason records the alien on his phone, Kyle slowly stretches out his hand towards the alien, with the alien doing so in turn. However, the alien pulls away suddenly after apparently sensing something in the distance - only for a sniper in the distance to hit it with two direct hits, although neither shot does any damage. Reacting defensively, the alien activates an energy shield generator on its wrist to deflect the bullets before rolling into a better position and killing the sniper with a powerful energy blast. As military helicopters fly overhead, Kyle shouts at the alien to flee - which it obeys.
At some point after this, Kyle and Jason were both arrested by the military and taken in for questioning. In his room, Kyle is interviewed about the incident by a man called Bishop, who shows him several different photos, including one of him and his brother on the day they met the alien. Bishop also declares that the alien attacked an entire platoon of his men, although Kyle defends the Alien's action by stating that it was simply defending itself. Believing that Kyle knows where the alien is hiding now, Bishop warns Kyle that he and his brother's lives will become very unpleasant if he doesn't comply. As Kyle refuses to say where the alien is, the lights in the base suddenly go out and alarms sound - with Kyle disappearing from his chair as the emergency lights turn on. As Bishop looks around with his gun drawn, he slowly turns around after hearing the alien behind him - which prepares to attack...
The alien was shown to have incredible strength as it was able to throw a basketball much further then any human could ever throw it, as well as been reasonably agile despite its size. It also had enhanced senses, as it was able to detect the sniper before he fired his first shot. The alien also possessed considerable intelligence - befriending Kyle, understanding human speech to some degree and managing to enter a military base undetected.
The creature's 'armour' presumably contains a respiratory system to help the alien survive in Earth's environment, as it can be heard breathing when its on screen. Its armour is also able to deflect bullets to some degree. In terms of attack and defense, the wrists on the alien's armour contain energy generators - which can be used for creating energy shields to defend the alien from attack or unleashing explosive energy blasts (although these need to charge up for a few seconds). Finally, the alien possesses 'dreadlocks', which can be used as a short range weapon - as evidenced by the alien intending to use them on Bishop.
Official Website - http://envoyfilm.com/