Oh you think you're so fancy, commanding giant armies, flying planes, driving trains, creating chemicals, and single-handedly gunning down every demon in Hell. Yeah, well, I bet you can't build a particle accelerator. Go on, try Atom Smasher without watching a tutorial. It's a short free engineering sim prototype about piecing together sensors, accelerators, colliders, coolers, electrical substations, and so many wires and pipes to make a functional particle accelerator. It's still early days for the game, but pleasing enough to warm up the sluggish skulljelly on a Monday morning.
You can grab Atom Smasher's prototype free on itch.io. It has four levels of particle-accelerating fun, each demanding you build a larger accelerator to reach a higher goal. More powerful accelerators are naturally more complex, demanding chains of cooling solutions, power boosters, sensors, and so many fiddly bits. There's something especially pleasing about the wiring, pulling individual cables out of bundles to run off connections. I admire clean, tidy wiring.
As you'd expect from a prototype, it's rough, but it works, and it's an interesting challenge. It has no tutorial so you should watch this demonstration video from creator Craig Perko if you don't want to end up with a billion-dollar paperweight. Perko talks about adding more parts and more variables to balance, as well as more levels, which sounds just splendid.