Founder's Mercy is very unclear about its backstory, but there are some hints to be gleaned from a Holy Book left on an altar, some personal memories of the protagonist upon entering locations and examining the surroundings.
You're on a generation ship sent out to the Lagrange 5 parking spot trailing earth in its orbit. (For those interested: Lagrange points are fascinating. The next huge space telescope will also be parked on one of them.) Your ancestors hoped to bring a civilization to fruition on this ship according to their godly laws. It didn't turn out that way and now you're the last one left.
Food and water are getting scarce and the life support machinery is slowly breaking down. Plus, you're yearning for human contact.
Founder's Mercy takes place on a very small map. Too small perhaps to give an accurate impression of the game world. It's only when you have the opportunity to look at the entire ship from a vantage point that you get an impression of how enormous it is.
Since you're on a wheel-shaped spaceship, directions are not the default N,E,S,W, but rather SpinWard, AntiSpinWard, Starboard and Port. This doesn't lead to any confusion however. The map is small, almost straight and circular. You can find whichever location you need by going SpinWard the required number of turns.
Like the backstory, the surroundings are not given a lot of attention. It's clear that the game wants to focus your attention on the puzzles.
The obstacles are quite easy to overcome. There was one that took a little bit of thinking around the corner, but it's mostly find-object-use-object stuff.
A nice and short diversion.