Once the helmet is removed, it was revealed that he is actually a bird. He also asks his son to remove his helmet.
In the cutscene, he sacrificed himself for his son and to kill Emperor Palpatine. When Palpatine is almost defeated, Darth Vader did the final strike. In the final level of Death Star II, he appeared, but the boss is Emperor Palpatine. After the level, there is a cutscene that he reveals that he is Luke's father. In the final level of Cloud City, he also appeared as a boss, but this time, he jumps from one place to another, while using his lightsaber. He also appeared in the second half of the Death Star chapter riding a TIE Fighter, during the Death Star trench run.
In the cutscene, he killed Obi-Wan Kenobi. He appeared as a non-mobile boss in the first half of the Death Star chapter. Darth Vader is one of the villains of the game.