This could make an interesting setting for a game, video or otherwise. Plenty of opportunity for exploration for the player(s). Would be essentially something intermediate between discovering new lands in an ocean and new planets in space. The ‘craters’ would share the same atmosphere, but would have mostly isolated biospheres.
One could even use this dumb flerf idea of a circle-flying sun and integrate it as an explanation: there are numerous tiny, but bright and hot sunlets floating over certain points of the planet, which make that particular spot habitable. Get too far away from your sun, and it gets icy cold. Would still need some handwaving why they stay over a certain area, but here, some variation could be added: in some places, it's essentially geostationary, no day/night cycle. Others circle around an invisible point in the sky, like flerfers imagine it. Or around a visible one, that's the moon equivalent. Or sun and moon circle each other. Or you have several suns. Or, your particular sun drifts, forcing the civilizations in it's ‘crater' to keep moving. Maybe it's even on collision course with another sun!