I really liked the combat, but what I hated having to deal with was the gas mask whenever you had to venture outside. I hated seeing the gas tanks run out and never felt confident that I'd be able to make it to more oxygen tanks.
The expendables was a nice little idea, but boiled down to a generic sort of action film with a few cameos. What was a joke was how they advertised him in the movie as if he had a big role.
Those people could never walk out of vault 112. They were stuck in their pods forever, until you decide their fate.
It probably comes down to cryogenics. Just like on Mothership Zeta.