I was recently looking at some actual extreme environment bases - artic, subaquatic, orbital - and marveling at just how tiny they are. Video games have unrealistically massive levels, it's true, but reality has unrealistically tiny levels a lot of the time.
There are a wide variety of video games, but most video games have the gameplay as the constraint and the levels as the opportunity. IE, you can run around at X speed, jump Y height, have Z weapons, now here is a level to conquer with those constraints. Whether we're talking about PacMan or Battlefield or candy crush, that's how it is.
If you decide your whole game will take place in one tiny location like, say, six people living in a schoolbus for a month, that won't work. The level is too small and has to last too long: it cannot be the opportunity part of the game.
Instead, it becomes the constraints.
If we consider the level as constraints instead of opportunity, we can start to craft a game where a tiny level can work. But we can't have a game with no opportunity: we also need to create an opportunity system.
One option we have is to make the gameplay elements into opportunities rather than constraints, and allow the players to craft their own gameplay. For example, if your base is a deep-space probe scanning the skies and doing science, you can allow the player to create more interesting science experiments and analyze a stream of unique data using customized heuristics. The level would be your constraints: only so many computers, so much memory, so many telescopes. There would be a struggle to do more with the same resources.
Another option is to have two levels: a closed level and an open level. For example, you are on a tiny scout spacecraft landing on a new planet. You only have a small payload for samples and limited time for analysis, so you have to decide what you can analyze and/or bring back. The inside of the space ship is a level, but so is the exterior where you go hunting for samples.
My favorite is the "ratcheted constraint" system, where you build/improve your tiny space between missions. In this form, the tiny space is an opportunity between levels, as you expand it and modify it. Then you have to live with it as a constraint on the missions.
That's the way Gravity Grain will work.
Well, either way, I think it will be fun.