This manga is probably the closest we are ever going to get to a LOST series-like manga. It has exactly the same tropes and the same problems: Too much bait(ideas) not enough meat(resolution).
The author got the notice 2 chapters ago to wrap it up because the initial boost and the great ideas seemed to die down because the MC Akira is boring. The story is basically the same thing: an escort mission. The exact same problem you had with LOST: the crew is useless, it can't make good decisions like: let's make shelters, let's look for food, let's start some kind of society, let's make weapons, etc. It keeps reusing the same ideas it did in the first arc: humans are dumb, animals are Deus Ex Machina who kill all the bad bad humans.
I think the author really wanted an anime series and I am all for that. I think a 24 episode series is much better than the manga because as it goes on, it kept losing steam. A 24 episode series can really condense the best of the manga and make a straightforward and steady story.