Factorio Space Age is partially set in space, which qualifies it for getting a Kerbal rating.

Remember, the Kerbal rating has nothing to do with whether or not the game is good, but just with whether it does space simulation in a physically correct manner.

With that, I give Factorio Space Age a Kerbal rating of 2/10.
Major points influencing the rating are:

* Space platforms lack RCS thrusters, rendering them unmanouverable.
* Transfer between planets uses constant thrust in a single direction, no orbital transfers of conventional rocketry or deceleration phase of theoretical, high delta v rocketry.
* No delta v readings.
* Oxidizer is in-situ generated from iron ore and water, two substances not known to be all that eager to accept electrons.
* Asteroid density is way too high to be realistic for low Nauvis orbit, given the suspicious lack of impact craters on the surface. Doubly so for other celestial bodies, with even bigger asteroids orbiting at what can't be a high orbit.
* Rocket launch does not execute a gravity turn.
* Dropping to planet does not accelerate retrograde.
* Items are transported via conveyor belts in a zero gravity condition, without being physically attached to the belt in any way. And yes, there are no magnets, I checked and plastic can also be put on belts in space.