What is a good offline game that will give you thousands of hours on the Steam Deck?

I currently work as a unarmed security guard and I work at a quiet site with lots of downtime. Once I finish my patrol I mainly sit in my guard shack with nothing to do occasionally letting in worker vehicles 3 to 5 times a week. I'm looking for a good offline Steam Deck game that will give me hundreds if not thousands of hours of gameplay to occupy my time. I'm not really picky about much I'm fine with most games including emulation.