There's a few things, though they aren't as developed as they could be.
- Survival game mechanics like food/water/toxicity. These are tuned as mostly a nuisance currently, rather than being a significant driver - mixed feelings here, not the biggest fan of survival stuff in general, but if you add it, it should at least matter.
- RPG mechanics - you level up various skills ( like running or survival ) through use, and higher skill levels also give you what are effectively gem slots where you can add what they call LEMs to the skill to give you various other bonuses/abilities.
-Tower defense mechanics - there are various turrets etc, and unaddressed alien incursions will result in them 'infesting' your bases, which disables all the machinery and surrounds it with a giant infection cloud that drains your shield etc when inside it. I haven't had the aliens attack a base that was a long way away, but I don't know if that is a rule or just coincidence.
- Modular weapons upgrades - apart from having way better guns than satisfactory, the guns are all modifiable with different mods you can buy with the 'war bonds' currency ( like blueprints, scavenged from other outposts/dead miners etc. ).