I’m trying to find a movie or series, it was an anime or some animation if I remember right. I watched it around 2010-2016.
I remember it had school students and they transport to another world or something similar like that. There wasn’t really anything, just ground and big rocks and I remember that the place looked like it was in the sky.
There were some weird ”monsters”, they were small and their shape was like a square block, they tried to kill the students, so then the students and ”monsters” fought and the students killed them I think. I also remember the students hid from the monsters behind the big rocks.
Also if I remember right the students could go back to their own world and then again back to the ”monster” world.
This is everything I can remember, its just how I remember it in my head, so some things are probably not right. I tried looking for this for hours but couldn’t find anything.