Key is different because Maeda is not only the idea guy and main writer but also one of the main music composers, and he typically composes the music to all his climactic scenes himself. The music is a part of his vision, and a huge part of Keys brand. Key works are not as much about telling logically sound and interesting stories as theyre about simply delivering emotions, and the music is instrumental (hehe) in that.
no matter how many times i see a bug eyed monstrosity die from magical keyaids i still get the feels when maeda hits me with shit like chiisana te no hira, aozora or haruka kanata.