So, people like to pretend they're creative. What is creativity? Complex question. But one thing is for sure: necessity really is the mother of invention. If you can't pick the obvious first choices, you have to invent new choices.
As a matter of fact, this is largely why theoretical physics has "stars" which advance it so dramatically. The vast majority of the scientists choose the obvious choice of existing methods and try to enhance them. Some scientists stop themselves from choosing the obvious choice and try to figure out another method. A few of these scientists succeed and change the face of their science.
In a dramatically less important example, I am kinda creative. No creative genius, but more creative than your average hairless monkey. And my favorite excersize is figuring out alternative "paths" to the same basic functionality.
For example, in the world of Machine City, there is no electricity. The laws of physics are just a tiny bit different. There is no lightning, no static electricity, no induction.
There are two things to be creative about, here. One is "what happens instead"? It would be fun but meaningless to bluff on this matter. As that is a very complex question which nobody who isn't a cunning quantum theorist could answer, I'll go in the other direction:
"How does society get around this?"
Electricity is excessively useful. It's probably the most useful of science's many discoveries and implementations. Something which can be generated a hundred miles away and piped to every room in every house in every city? Then it can run lights, air conditioners, security systems, televisions... moreover, even the basic idea of the telegraph operates on electricity! What kind of communication will you have?
Take electricity away. No electric lights. No television. No phones. It's like living in the midieval ages. Except that the first-world countries of the Machine City world need to function like something between the 1890s and 1930s.
For lights, I chicken out. There is a set of chemical compounds which, when mixed, glow brightly and at low heat for many hours. In addition, there's a "spinnable", which is a long tube filled with a substance which glows when agitated. Spinnables are spun to get them to glow, or shaken when used in flashlights. They are noisier, but require vastly less maintenance. The most modern spinnables are called "whisper lights" because they produce almost no noise save the gentle "shush" of the particulate matter circulating inside them.
But for everything else...
I want everything. Computers. Quick communication. Security systems.
And I have to use mechanical power to get it.
Where would you start? Think about it for a second, before I tell you what I did.
Here's what I did.
One of the things which enables the modern world is centralized provision of water and electricity. When indoor plumbing is simply a matter of tapping a watermain, you're more likely to have indoor plumbing than if you'll need to build a pump yourself.
So, I needed centralized mechanical power.
Unfortunately, mechanical power doesn't transmit quite as losslessly as electricity. There are, however, more and less lossy ways of transmitting it. The least lossy and least maintenance-heavy way is using water pressure, then having a mechanical converter for the building which pulls belts that distribute power over the rest of the building. Or even one converter for each floor. These are usually provided free by the water company so they can charge hefty monthly fees for water pressure usage.
Now, most of you have played video games in which you've moved through air ducts. Good stuff, right? Some of you have probably played video games where you move through empty water pipes. Sewers, for example.
With the amount of water inertia required to generate enough power to run machines and pneumatic message tubes, buildings aren't going to have those tiny water pipes you're familiar with. A measly six inch pipe? No way. They're going to have big honking pipes. Large enough to enter, should you figure out a way not to get turned into puree by the turbine.
In addition, the belts which distribute the power locally will need to run through a crawlspace that can be accessed to repair the ever-wearing belts and wheels. The noise in these crawlspaces would be tremendous, and often these crawlspaces would have exposed rapidly-whooshing belts. And we're not talking little car-engine belts, nuh-uh. We're talking two foot wide steel mesh belts, and wheels with hooks all over them.
As you can see, I've created a building with a whole new feel to its innards. In addition to the normal hallways and air ducts, I've created belt-fan crawlspaces and big honking water pipes (which may have their own sizeable crawlspaces). Also, the huge machines will be paths in and of themselves, with walkways and catwalks to access any part that needs repairing or tweaking.
Managing this power is a bit wonky, if we look deep. For example, what do they have instead of wall plugs? They still have wall-plugs (actually, floor-and-roof plugs), but plugs that are half a foot across and have teeth. You plug something in, pull a switch, and the assembly rotates, driving your machine. Very noisy.
There's a mechanical contrivance which limits how much power your converter takes, essentially a gear shifter. Similarly, your turbines can tell how much torque they need to generate and can automatically pull that much energy from the city's water pipes.
In turn, measuring the pressure of the water in the tubes can show you how much energy is being taken from the water, and how hard your pumping station pumps can be altered to fit how much energy is currently being used. This isn't an instantaneous reaction, so it isn't uncommon for buildings with large power requirements to have an hour of "brownout" where everything is spun too slowly, until the pumping station picks up the slack.
Similarly, you can't instantly accelerate a belt or shaft to full spin, and the larger the power requirements, the longer it takes to spin up. This means that those big machines may take many seconds or even minutes to spin up to speed.
What we end up with is a bizarrely flavored world. Flipping on a light causes the lights to slowly spin up, dim at first and growing brighter. Or it causes a mechanical device to intermix two chemicals in a spray of wobbly light until the reaction stabalizes.
Turning on a computer is a process involves minutes in which it runs at partial speed. Unlike an electrical computer, mechanical computers run as fast as their spinning belts let them (until their little cogs snap under the pressure, of course). More power, more computation. A very "she cannae' take much more, Cap'n" situation.
Security doors can slam down quite fast, but raising them takes time. Security locks which read punchcards don't require much energy, so they'll go nice and fast - but since it's kind of expensive to hook them into the power supply, they may very well be hand-crank powered!
Unique noises, lights, and architecture are an obvious result. Unique dangers, too. With this many moving parts, moving so quickly and so heavily, damage to buildings is fairly common. Fun!
And through it all, a variety of alternate pathways to navigate the building by.
The computers I've designed are an essay all their own. Fun!
Of course, Machine City will see little of this. It's a shmup. But the detail work will show in the backgrounds. :)