I feel like it needs a second part. Like what about the background of the whole thing? how did it start? How did they control it? The antidotes..? I really thought that these parts would be included in the movie like Gong Yoo might be the one to find out these things and you know it'll be a proper complete story. But this was literally just about the TRAIN to Busan. lol. So nevertheless, I hope they'd have a sequel? But I guess since GY dies in the end, even that wont make sense :/
thanks for the visual treat ahahaha