Normally you watch a disaster movie to see the rescue work, people saving others even though it may endanger themselves and for the feeling of hope you get. Haeundae is not really like that.

Most of the movie is pre-story and the story where people are trying to survive is like 10 minutes of the movie, so not really much. The pre-story holds a lot of "trying to be funny" humor that in my opinion is just too much for a natural disaster movie and a lot of the characters are just not like-able in any way and, I have to admit, I did not see myself rooting for most of these characters during the disaster.

It does have some people finding the strength to care for others and some people taking a sacrifice for others, like you would expect and hope for but it's mostly unlikeable characters having the best ending and almost no character development after.

The cast itself is pretty great and did good with their acting and I did enjoy our two main characters a lot. So compliments for that.
Overall, Haeundae is a good movie for when you have nothing else to do and want some good old Korean comedy mixed with a natural disaster. But as for a natural disaster movie, it is kinda disastrous.