An engineering game, as I'd define it, is a game where a primary gameplay element is designing machines for some purpose, weighing conflicting needs such as cost, versatility, and performance. I've only played a handful of these games, and I really wish I could find more. Here are some of the ones I've enjoyed:
Kerbal Space Program: I'd call this a definitive example of an engineering game, and one I have hundreds of hours in. I absolutely love designing rockets, figuring out what I'll need for each mission, experimenting with different staging mechanisms to maximize fuel efficiency, pushing my available tools to the absolute limit to land on far-off celestial bodies, etc.
Automation: The Car Company Tycoon Game: Yes, I know, fuck cars, but I'm having fun with this one. There are a lot of different niches you can cater to, and I enjoy specializing in affordable, reliable, fuel-efficient sedans and compact cars against the trend of turning everything into a gas-guzzling behemoth.
Master of Orion: Yes, a DOS game from 1994, and primarily a 4x, but its ship designer has some of the best balance between simplicity and depth I've ever seen. Ships have a limited hull capacity, but no fixed number of weapon hardpoints, and they can only fit a handful of special modules, but there are dozens to choose from, with widely varying capabilities. The number of actual choices to make is small, but they involve balancing so many things - durability, damage reduction, damage output, armor penetration, weapon range, maneuverability - and the turn-based combat gives enough control to let you really appreciate the impact your designs have.
Avorion: A space flight sim with highly customizable ships built out of blocks, with fine-grained control over things like engine power, maneuver thrusters, and armor thickness, and cargo bay sizes. I wanted to like this one, but it's way too grindy for me (building up your reputation with factions takes forever, and they won't let you buy better ship equipment until you do).
Robocraft: A game where you design a robot and then pit it against other players' creations in online team battles. My best creations were a spider bot that could scuttle up and over hills and ambush enemies with a massive plasma burst, and an air defense bot with bigass twin AAGs and a shitload of top armor. I had a lot of fun with this one back in the day, but nowadays it's so deserted that most of the players are bots.
Does Dwarf Fortress count?
I feel like it counts because half the game is designing incredibly elaborate ways to automatically delete siege attempts and invasions.
300 goblins? Release the lava reservoir we pumped from the depths of hell earlier.
Minecart machineguns
Supply chains. Requirement to trade for resources if you do not have resources available locally. Keeping various resources on hand because they might be needed for a sudden mood.
Yeah it's definitely an engineering game. Even water pressure is a factor in contraptions.
I tried to get into Dwarf Fortress but bounced because it was complicated. Might give it another shot. I had a lot of fun playing modded Rimworld and setting up rings of pillboxes and minefields and razor wire to make my colony impenetrable, and Dwarf Fortress sounds like it could scratch that same itch.
DF gives you a lot of components you can assemble to do all kinds of things. Lava cannons are popular, land mines made by caging an arbitrary number of dogs inside a single tile then putting it in the way of monsters that destroy buildings, contraptions that can drop the entire space around your fort in to lava with the pull of a switch. Plus the dorfs themselves are components that can be tasked and set loose.
The only thing you really need to understand are stockpiles and labour orders.
Your dwarves collect things and put them in stockpiles.
You build workshops.
You set labour orders with things like "make 5 drinks if drinks are below 50".
This gets automatically assigned to a workshop by a dwarf assigned as an administrator with an office. (middle manager)
Then your orders for creating those drinks are sorted. Now all you have to do is concern yourself with making sure the raw materials for those drinks are going to your stockpiles, and hopefully that you've put the stockpile for those materials not too far from the distillery where it'll be made. This is done by farming or by plant gathering. Which is again something that can be set up with labour orders.
Once you understand stockpiles and labour orders the whole thing clicks. You do not individually assign tasks for dwarves to do. Your dwarves do that. You just set up the chains and locations of stockpiles and workshops.