From LEGO Batman Wiki
Superman is a character that appears in Lego Batman 2 DC Super Heroes. He appears in quite a lot of the missions where he assists Batman and Robin. Like most characters, he has special abilities. Superman's special abilities include his heat vision and his freeze/wind breath. A cool fact about Superman is that his theme song plays when he flies in Gotham City.
Relationships with characters
When Batman and Robin first see Superman in LEGO Batman 2: DC Superheroes, they find him quite nice. Robin loves him all the time, sometimes even acting like a young school girl! However, Batman doesn't seem to like him too much as he believes that Robin likes Superman better than he likes him. Throughout the game, Batman comments on his dislike for Superman and sometimes trys to hide from Superman whilst he is talking to Robin.
As in the comics and movies, one of the only things that can kill Superman is Kryptonite. Throughout the missions, Joker and Lex Luthor are collecting Kryptonite to power their gun and kill Superman. They even use a fake Kryptonite to track down the Batcave, thus destroying it. On the level 'Destination Metropolis', there is Kryptonite on parts of the floor and when Superman trys stepping on it, he will back off, just like if he was touching electricity.