SettingPlanetSpit

Setting (Spitball) -> Religion

Mascons
"Mascons" - Uneven mass concentrations throughout the planetary body cause variations n the gravity of the planet. Mascons can be in the form of extremely large concentrations of a dense material such as metals or something more unnatural such as some kind of energy source or even magic. These location on the world could be common or rare; and either a great source of competition for holding that piece of land (or water), or an extremely dangerous environment.

http://web.mit.edu/newsoffice/2013/an-answer-to-why-lunar-gravity-is-so-uneven-0530.html

This idea could be expanded further or changed in the way it is represented. Rather than "Mascons", this gravitational anomaly effect could be achieved by large and/or close orbiting bodies; moons, planets, asteroids, etc... Assuming that the orbiting body has enough mass and is close enough to effect the world.

Tidal Lock with a Gas Giant
The planet could be tidally locked to a gas giant. This could create light gravity on one side of the planet and heavy gravity on the other side. As the planet orbits the gas giant, the low gravity half would fall in the shadow of the gas giant at night, and only receive reflected light from it during the day, while the high gravity half would receive harsh direct sunlight during the day and only starlight at night. This condition could exist with the planet having a rotation as well, creating a complex cycle of varying degrees of light (and gravity) going from harsh direct daylight to starless nights facing the dark side of the gas giant.



Also with the tidal-locked idea, the world could be much armer on the exterior side that gets deirect sunlight, and cooler on the side facing the gas giant. The water on the planet could be largely or completly locked up in a large frozen region most directly facing the gas giant. The lost civilization of the planet could have lived on the heavier gravity side which would be more conducive to crop growth, but in a "classic martian" stlye water could be trasported by canal from the icey side.

Arcanosphere
Magic doesn't exist throughout the universe. It requires some sort of conditions for its existence, so some planets have it while most don't. We can represent this by the concept of the arcanosphere, the spheroidal zone of magic around a source. This is what caused the spike in energy output of the power source leading to the crashes onto the planet. A world that has no arcanosphere would have no way of understanding it's effect or detecting it's presence. In the case of the gas giant moon idea, I think the arcanosphere should be based around the gas giant, creating a huge zone of magic which forced the second ship to enter it before being able to detect the condition of the original crash and any possible causes.

Frontier
The current thought is, in order to maintain a largely unexplored area of the planet for adventure, the far side of the planet is home to progressively more dangerous predators as you approach the apex of gravity. In this way, any but the most determined exploratory efforts would ultimately result in a big pile of poop with a seed somewhere inside it. Because of this, there would be large portions of the world that would still be open to the party exploring and finding new things, even though the automatons have been on the planet for a millennium. This would also be location of the majority of the ancient race's ruins, which would create something worth finding for the party. Because the majority of life on the planet would be on this side, their would be lots of options for undiscovered monsters and treasures.