Rover Mechanic Simulator comes from Pyramid Games, developer of upcoming survival game Occupy Mars, in which we'll explore and live on the Red Planet. You're also on Mars in Rover Mechanic Simulator, but you don't get to go outside and kick Mars dirt around. You are stuck in your workshop, repairing what are essentially RC cars for everyone else on the planet.
It takes some creativity to give you things to do in your workshop. Early repair jobs require clicking on rover parts to scan them for damage, holding the right mouse button over screws to remove them, using a 3D printer to make new parts, and then putting everything back together. It is much easier than actually repairing something small and complex, which if I were involved would involve several bloodied fingers and some amount of cursing.
To add a bit of flavor, you also have to pointlessly maneuver a ceiling-mounted grabber and solve a simple circuitry puzzle for each job. It's a simple routine.
Later repair jobs involve a bit more—you can repair PCBs with a soldering iron, for instance—but it doesn't seem like Rover Mechanic Simulator ever gets super granular (mind you, it's in Early Access right now). It doesn't need manual machining or serious electrical engineering, though. There's an inherent pleasure in disassembling something complex, such as a wheel housing, and then putting it back together again, and here you don't have to worry about dropping a screw.
What's most important in a game for rover-heads is the rovers. I am not an expert on Mars exploration, but the schematics in Rover Mechanic Simulator strike me as authentic. NASA provides detailed information on its rovers, so there's a lot of material to work with—see a 3D model of the Spirit and Opportunity rovers below, for instance.
I'm not gripped by Rover Mechanic Simulator and I doubt I'll play it much more, but I am charmed by its sincere appreciation for rover engineering. It's the antithesis of joke simulator games, which complicate mundane tasks or turn goats into wrecking balls. It's also not about designing new physics toys, as in Kerbal Space Program. It's just about appreciating, and fixing, what already is.
Rover Mechanic Simulator will be in Early Access on Steam for "several months."