Sort of like a cross between Monster Hunter and Subnautica. You’re one of a batch of explorers/scientists/critter fighters who get stranded on an uncharted planet somewhere and decide to make the best of it. Your goal: do what you came here to do, namely establishing a thriving research base and the beginnings of a sort of zoo, but also find a way to either get someone off the planet to go for help or at least signal for assistance. 

Heavy focus on exploration, on research and science, on sample collection and using the resources around you without damaging the local environment. You and a collection of NPCs first have to set up a few huts, then figure out a way to get to a better area and set up a large, protected, safe base. Because you’re all nerds, you spend the whole time you’re doing that collecting plant and critter samples. Once you start to set up the base, you can build a large aquarium and some ponds, some gardens, and set up what amounts to a museum-slash-zoo, which you fill with specimens for your research, enjoyment, and profit. 

There’s a range of things to do. Everywhere from collecting plants to garden for food, drugs, research, and so on, to searching for metals and other inorganic resources, to catching small creatures to study, to building small machines, to fighting medium and large beasts. Even taming some of them! What you can’t tame, you ward off or take down, and add whatever you can of it to your research. Lots of exploration, too, maybe finding a few secrets of people who’ve been here before.

Eventually, you can reestablish contact with the people who sent you out in the first place, start up a bit of trade with the main research center back on your homeworld, and recruit a few more NPCs. 

And there’s NPCs to make friends with! Possibly some flirtation. A decent number of them are probably going to need to be distracted in one way or another from the circumstances, or they’ll be upset and not very helpful. If they’re calm and happy, or if you’ve got the base set up nicely, you can send them out to do research and gather materials for you. 

There might even be a native, sapient species to befriend. A bit carefully. They might not be terribly keen on you at first.