Eden no Ori, EX: Shounen Hyouryuu Recommendations
Both mangas features protaganists that are children.
In both Eden No Ori and EX - Shounen Hyouryuu the protoganists strive for survival. The mangas also give off the same feeling of hopelessness and is similar when it comes to showing human psychology. People die in both of these mangas.
One major difference is that in Eden No Ori the protoganists gets stranded in a prehistoric enviroment, while this is not the case in Ex - Shounen Hyouryuu. Although do not fret, they are both quite similar and if you like either one of these mangas i strongly recommend you giving the other manga a shot.
Teenager got stranded on foreign place. strugling for survival.
They both have a young main protagonist, where will protect the girl they like. They are both on an island, and the start and the end is similar (it's how you look at it). In Eden no Ori there is more mystery, and of course they are both mangas where they need to fight to survive.