Oh boy this is one of those topics I wont shut up about if given the chance. I'll try to contain myself.
Firstly I must of course mention Minecraft. I dont think I need to explain too much about it, anyone who plays games likely knows how it works, but I do want to show something really specific:
And yeah, I know, that kinda looks prerendered at first. It isnt.
I've heard this referred to as the single greatest mod ever made for the game, and that's one heck of a tall claim. But after seeing some of it in action... yeah, I can believe that.
This isnt like, say, Tekkit either, or one of those older automation mods. No, this is a full-on engineering mod, as you can probably guess in the trailer when things happened like part of the freaking building suddenly pulling itself off and sinking into the ground. You should see what sorts of loopy things people have made with that. And of course, this all combines quite nicely with the usual Survival mode. They also have released a big modpack that takes it a step further, where your goal is to launch a rocket, but of course you're gonna have to make a whole factory and crazy stuff like that. This is a Forge mod, which means it generally plays nicely with, well, other Forge mods.
Stuff like this is the reason to pick the Java edition over Bedrock. Just be sure to also be using something like Optifine or a different optimization mod also... Minecraft just by itself likes to try to eat your GPU and such, but a mega-mod like this will bring your PC to its knees if you arent careful.
Speaking of factories we've also got:
Yeah I know this game isnt exactly new, but I know not everyone who sees this topic will know about it so I'm gonna ramble about it anyway. Your guy crash lands on a random planet, mostly uninhabited but also full of truck sized roaches for some reason (a problem you'll have to deal with later), and your goal is to build a ship to get off this rock. Like all games in the "automation" genre that this spawned, you'll start out very slow, doing a bit of mining by hand to construct your first couple of gizmos... which will get the mining automated... and soon you'll be building assemblers that you've set up to build more assemblers for you. This is one of those games that really does everthing it can to respect your playstyle, and not try to funnel you into playing the "right" way. Are you really efficient? Or do you make ridiculous spaghetti disasters like I do? Doesnt matter, it supports your playstyle and you can still reach the end goal. Like Minecraft this also has full modding, and all sorts of screwball things have been made for it. Though I strongly suggest NOT touching any of the major mods until you've launched the rocket at least once. Almost all of the mods increase the game's complexity and challenge even further.
So this is basically Factorio, but played in first person in a fully 3D world. Which can be both good and bad. On one hand, yay, 3D! On the other hand, now your conveyor tangles are in full 3D! Or maybe that's just me. You can build entire giant structures to house your factories in, if you like, or just leave the various machines all over the place if you like. This is a VERY polished game and is hilariously made by the same guys who made Goat Simulator.
Okay look I could talk about JUST factory games for ages here, this particular genre outright exploded after Factorio happened, but those are the two to start with if you find yourself interested. Definitely the best introductions to the genre.
Pico-8 isnt really a game on its own. I'll just let the thing's site speak for itself:
PICO-8 is a fantasy console for making, sharing and playing tiny games and other computer programs. It feels like a regular console, but runs on Windows / Mac / Linux. When you turn it on, the machine greets you with a commandline, a suite of cartridge creation tools, and an online cartridge browser called SPLORE.
The harsh limitations of PICO-8 are carefully chosen to be fun to work with, to encourage small but expressive designs, and to give cartridges made with PICO-8 their own particular look and feel.
If you've ever heard of Celeste, that game started out as a Pico-8 creation (which, needless to say, helped get people more interested in this). There's a lot going on here, and anyone who enjoys the idea of programming challenges is probably going to like this. I havent sat down with it myself yet, but I do intend to.
Pico-8 is not found on Steam. Instead, you gotta go here:
PICO-8 Fantasy Console
Something that's particularly notable about this one is that games made by it are easily shared, even outside of the main program itself. You dont have to have Pico-8 to play games made in it! Which is probably why Celeste exploded.
And lastly, I'd also like to list, well... (almost) every game ever made by Zachtronics. I mean, okay, I'm not actually going to list them, just put that name into a browser and prepare yourself for a deep rabbit hole.