Just finished it. I found the ending kind of fitting. He saved one family when in all likely hood, he wouldn't be able to save his own. A personal salvation kind of thing. I'm a huge fan of bad endings (Main character dies, the goal ends up failing by design, and just shit going south in the end.), so it worked for me.
Also, that mutant thing is totally accessabile be doing a little climbing around. If you decide to help him, which takes a lot of resources, he gives you something awesome.