Hello everyone!=) So, basically I am looking for (korean) movies that have a similar concept as the one developed in A Million. But, anything involving survival in groups would be great. I also loved The Tower and Haeundae. So, suggestions about apocalyptic/disaster movies are welcomed as well. Thank you in advance!
These come to mind at the moment. They are Japanese though.

Pandemic (Japanese) http://mydramalist.com/korean-movie/910/pandemic
Dragon Head (Japanese) http://mydramalist.com/korean-movie/2179/dragon-head
A drama that might fit Long Love Letter http://mydramalist.com/japanese-drama/476/long-love-letter
i've also thought of japanese ones. battle royale liar game
Thank you very much for all of your replies! I'll check the movies out. I'm still new to Japanese movies/dramas, so this will be a great opportunity to get to know more about them. So thank you!^_^
Incite Mill 252:Signal of Life both are very good.
wsa67 wrote: Incite Mill
252:Signal of Life
both are very good.

Thank you! =)
White Christmas - psychological thriller with a group of high school students who bond with each other to try to escape from a serial killer who trapped them in the school!
deranged it's one of my favorite movies, i'm sure u'll like it
I appreciate your help!^_^ About Deranged... Some time ago I saw that the movie was available on Dramacrazy. Now that the site is closed, I can't find it anywhere.
It's on asian-horror-movies.com/Deranged.php or download on asiatorrents.
Pien82 wrote: It's on asian-horror-movies.com/Deranged.php or download on asiatorrents.

Oh, thank you soooooo much for posting the link. I'm going to watch it right now!
The Tower

IkPien wrote: Dragon Head (Japanese) http://mydramalist.com/korean-movie/2179/dragon-head

Any idea where to watch or download this movie?