Tried a speedrun last night just for fun, and I beat it in just over an hour. On the lowest difficulty, mind you, but if you know your way through it can be really short. Was also fucking around on my other save file, looking for other uses for the Atomic Batteries, but seems all you need them for is the Interchange. While I appreciate the large number of them that you can find in the world, I would've appreciated some heads up that they're kinda worthless outside of story progression. Would've been cool to spin up one of the IFV/light tanks that clearly has a slot for atomic batteries and charge into a base.