I grabbed The Talos Principle for dirt cheap (-90%, Steam's autumn sale) and already sank several hours into it. An excellent puzzle game that starts off easy but gets increasingly challenging fairly quickly. Six years old but visuals are fantastic, and even my PC runs it perfectly at max.
It's tagged as philosophical and sci-fi, and although user-assigned both tags are spot-on. Not exactly my favourite themes, but I'm enjoying it all regardless. Full controller support makes for a comfortable experience, though I did switch from the default control mapping to another preset (Who uses RB for jump? A bizarre default.).
Hopelessly (for now) stuck on a puzzle... but the harder it is the more satisfying it will be to finally figure out the solution.