Same movie for me and same impression too. Not sure if the monster's were even necessary. Also it had more of a "run away from the explosion" vibe than a "oh this uboat is about to implode" vibe. But I can confirm it is ok-ish.
Edit: That's crazy. I've looked at your profile since I thought it's a funny coincidence. I've also lived in South Korea for a while and I've also used Pop OS in the past. Really interesting. May I ask what you are doing in Jeju-Do?
Interesting! Hope your school goes well. Pop OS is an operating system. I guess it was just a coincidence you commented there.