Yeah, some of the mid-to-late game missions can take an hour or more of multi-floor / large complex arena battles. It can get pretty crazy. But the early game stuff should be okay. I'm thinking you can't save mid-battle though. And phone games would be prone to idling out. Though for android I know you can access console commands and put in things like god mode and stuff, so you can experience the story and stuff pretty quickly in those if you wanted