Is it possible to complete Shelter without losing any cubs?
I made it through the first two areas without losing a cub. I lost one in the third area, and one in the final area, but I'm pretty sure that I could have avoided both losses if I had been more careful.
Based on what I saw of the levels, I'm fairly certain it's possible to complete Shelter without losing any cubs. Be on your best guard, and keep a close eye on your young.