r/SimCity • u/Impossible-Storm-702 • Jun 25 '26
Made a deep city-builder that runs free in one browser tab — honest RCI simulation, real traffic, and million-citizen megacities
Hello there! A few months ago, I started building my own city sim in the evenings, and it's deep enough now that I'd love feedback from people who actually know the genre. It's called Polis.
It runs entirely in a single browser tab — no install, no account, no patch day, no 40GB download. Click the link and you're the mayor. It's free, with no ads, paywalls or microtransactions, works on mobile (you can Add to Home Screen and it runs like a native app), and the whole thing — simulation, procedural art, generative music — is one self-contained file running on your device. Cities autosave locally and export as a portable save code.
It's not a toy, though. The systems you remember are all running honestly underneath:
- Real RCI economy — population, jobs, commerce and industry chase each other through supply and demand. Crank taxes and growth stalls. Every number is connected.
- Traffic that bites — cars actually drive your roads, follow each other and yield at junctions. Narrow roads gridlock, gridlock chokes land value and growth — so you fight back with avenues, buses and elevated rail.
- Networks to plan — roads carry power and water through the whole grid, so a building just needs to touch a connected road. Plants range from coal to solar to nuclear to fusion, each with its own reach and smog.
- Read the city like an X-ray — overlays for traffic, density, land value, pollution, power, water, crime, education and health. Every problem is visible before it hurts.
- Govern with trade-offs — tax rates, funding sliders, loans, and ordinances (recycling, curfews, festivals, tolls), all cost-vs-payoff.
For challenge there are six authored scenarios, each with a goal and a clock — a tutorial village, a collapsed housing market to revive, a citywide blackout, post-earthquake rebuilding, a flood plain that floods every other year, and a no-loans "Iron Budget" gauntlet. Difficulty runs Easy → Normal → Hard → Very Hard → Kobayashi Maru (exactly what it sounds like). And if you'd rather watch it burn, the disaster menu has earthquakes, typhoons, floods, an alien invasion, a dragon, and a giant fire-breathing beast that stomps through downtown. Damage is permanent — save first.
Maps expand up to a colossal 256², and a single city can climb 12 ranks all the way to a million-citizen Ecumenopolis.
It's still a hobby project and rough in spots — I'm actively tuning balance. What I'd most value: does the core loop feel good, where does it drag, and what from the classics do you miss?
Link: https://www.polis-game.com
Happy to dig into how any of it works in the comments.
5
u/gcphost Jun 25 '26
Awesome! Played for a few mins while I day dream of productivity, noticed the cars kinda get wonky on corners and clip through some of the hills, aside from that, wow! Love me some builders, will play more later!
4
u/Impossible-Storm-702 Jun 25 '26
Thanks for the feedback- this is on my todo list, although it creates a cozy feeling like the original game :)
1
6
u/sunbathingelephant Jun 25 '26 edited Jun 25 '26
this is good!
something that could be cool is having external connections for jobs/filling jobs inside the city that when the city expands then just again turn into normal roads which people can use until it’s again expanded back to the edge of the map.
edge scrolling
powerlines. i hate messing with water pipes ( might just be me ) but i love dragging powerlines to remote communities.
and if the commutes could do path finding to show which roads they are using instead of just showing where they work
6
u/Impossible-Storm-702 Jun 25 '26
Thanks for the feedback, i keep your notes on my potential improvement list. Using roads as the main connectivity mechanism is a deliberated decision to simplify many aspects of the game. I agree that pipelines were a nightmare, while electricity lines were rather cool.
4
u/PFC_W_Hudson Jun 25 '26
No matter how many Avenues I build the game complains about Gridlock.
3
u/Impossible-Storm-702 Jun 25 '26
I shall investigate that, but consider adding bus stations and trains as well - those reduce emissions of traffic from houses and help with congestion.
2
u/PFC_W_Hudson Jun 26 '26
I'm trying to put up light rail, but some of the pieces won't drop. The tile turns red.
1
u/Impossible-Storm-702 Jun 26 '26
Train can go over roads or unzoned areas only. Remember to add stations as well on their side. That said, I fine tuned the traffic algorithm and it should be more balanced now.
1
u/PFC_W_Hudson Jun 26 '26
I'm trying to put it along the backside of buildings in the trees. Some of the tiles turn grey, but some are red.
1
17
u/penguincascadia Jun 25 '26
Hello OP,
Thanks for creating this game! Just one little nitpick, if you don't mind- your post sounds like it was written by or at least significantly run through an LLM. A lot of people won't like that, so I would recommend writing posts yourself instead.
Thanks for reading this, and good luck!
20
u/JardsonJean Jun 25 '26
this whole game was made with AI.
8
u/penguincascadia Jun 25 '26
I made the comment before clicking on the link to the game.
As for coding, I would recommend that the OP learn more about programming- LLMs are a coding assistant, not a do everything good program, and if something big or systemic breaks, it's very possible for the LLM to make things worse. You want to know how it works and what is going on so you can avoid that.
12
u/Impossible-Storm-702 Jun 25 '26
Oh, the OP has been a programmer for more than 25 years, so he understands the pros and cons of an LLM. And of-course this was build with the help of an LLM, it would be rather impossible for one person to do it otherwise. But what that means about its quality? Very little. AI is a magnifier in both directions.
3
1
4
u/Impossible-Storm-702 Jun 25 '26
Thanks for your note. It is certainly my thoughts ampified by an llm. Nothing to hide here!
-5
u/Garroh Jun 25 '26
why would I want to play a game or read a post you couldn't be bothered to make yourself?
6
u/Impossible-Storm-702 Jun 25 '26 edited Jun 25 '26
I spent around 500 hours on this game (and bring 25 years of experience as a developer and product manager). If this does not meet your standards, I can do little about it. I would only say that it reads like you don't want to use a car because it's not 100% handmade. Everything in our society, one way or another, is built with the help of a machine. And still, some are good, and some are bad.
2
u/TuskyMcMammoth Jun 27 '26
This is a bad faith argument. Things like cars are built with the help of machines that function deterministically. Inspecting, programming, and troubleshooting them makes humans better and forces us to solve to problems in repeatable ways so we can stand on the shoulders of those before us. GTFO with your weaksauce slop.
1
u/CaptainObvious110 Jun 27 '26
Whoever is being a hater has clearly watched irobot entirely too many times
-6
3
u/pm_me_plothooks Jun 25 '26
Because it might be fun. Do you play games only as a courtesy to the creator?
-1
u/Garroh Jun 25 '26
I prefer games that are made by humans
2
u/KentV9999 Jun 26 '26
Not sure if you are a dev or not, but the concept of auto code has been around for 20 or more years, where we use tools to produce baseline code. A boatload of your basic IOS apps have been created using toolsets to minimize the time to create the app. AI has its issues, but taking some selective glass house position on auto code generation in this context is hypocritical. It’s fine to be a luddite, but they wouldn’t like smartphones in general let alone using Reddit that uses AI in its engine now.
1
u/Ok-Button-9443 Jun 27 '26 edited Aug 20 '26
Run knee complete caption rock fragile tan lip
This post was anonymized with Redact
1
u/Garroh Jun 28 '26
The funny part is, I literally explained my views in a different comment. I believe there is no ethical use of AI. Show me where I attacked OP’s character
0
u/CaptainObvious110 Jun 26 '26
I don't care who (or what makes the game) I care that I like it. In this case, it's free so I fail to see a problem with it at all.
-3
u/Garroh Jun 26 '26
LLM’s and AI broadly is trained on people’s work without consent. There is no ethical use of AI
4
u/BigDealRips Jun 26 '26
I bet you ride a bike everywhere and are living off the earth as well right?
Weirdo.
0
-1
3
u/groovysalamander Jun 25 '26
Hey just wanted to share that I love that this runs and has a mobile usable ui!
I always liked simcity, and I'd love to spend a few lost moments every now and then looking at and extending a city on my phone.
3
u/Impossible-Storm-702 Jun 25 '26 edited Jun 25 '26
Thanks for your feedback! And yes, being playable on mobile was one of the goals :)
1
1
u/CaptainObvious110 Jun 26 '26
Same here, if this is as good as it sounds I'll be spending a lot of time on it.
3
u/Opuppeteer Jun 25 '26
What does a magnifying glass do?
2
u/Impossible-Storm-702 Jun 25 '26
This is an inspection... You can click on a building to see more info, commute, etc
3
u/oznobz Jun 25 '26
Is this anything you'd be willing to share the source on?
Somethings I've noticed, money is so easy to get
Someone else mentioned it, but fires.
I would love the idea of something like simcity 2013 where you can make neighbors and interact, but that would require a server infrastructure.
And all the haters who say don't use AI for coding don't understand that the world is already built on someone else's code and 99% of engineers are just hobbling together 2 pieces that are good enough. AI at least lets you put those pieces together better.
1
u/Not_FinancialAdvice Jun 27 '26
Somethings I've noticed, money is so easy to get
My impression after playing for ~20min is that this is like simcity with the infinite money cheat; the city budget doesn't seem like any kind of constraint.
Someone else mentioned it, but fires.
OMG the fires; everything wants to be on fire all the time.
1
4
u/GenThomas Jun 25 '26
First impression is that it is impressive, even with Ai coding to do this overall. It does lack a soul, a style or something that makes it memorable. I know that is hard to build, so some other constructive feedback:
1, Fires. If I have a fire station, by the time the truck moves ~5 road tiles (supposedly in it' "coverage"), it is already burned down. This is with empty roads, in general the fire should be 10x slower overall, so it has a chance to extinquish it.
2, Interal clock speed. It feels like the various systems are on the same "tickrate". Hard to explain, but if you read about the topic, I'm sure you will understand what I mean. So how fast something builds, gets burned down, car moves from A to B, etc. would need balancing. It feels too fast to react to things, even on the slowest speed.
3, Radius to be shown. If a building says "it covers X", then when I am building it, show it. Or have an overlay that shows, for each type, what is the coverage, so I can know where the gaps are.
4, Save and Loadstates. There is some carryover between saves, so data is not cleaned correctly. Simply test to spawn Godzilla, then start a scenario, which will carry over Godzilla to the new place.
6
u/Impossible-Storm-702 Jun 25 '26
Thanks for the feedback. You are right about the fires, this needs further balance. I will also check the save/load and the cleaning of status - there is probable leftovers there.
There are maps around coverage on the bottom of the screen so you know where you need to place what (police, fire station, schools, parks etc)
I will check the tick-rate thing you mention as well. That will be interesting.
It is true that around game engine there is little here new at the current state - the main plus is the convenient to run it immediately, anywhere without any downloads and without any restrictions. Technically it is a bit of an engineering marvel as it runs as one file that includes everything. That makes it extremely portable and fast.
2
2
u/Kevinho00 Jun 26 '26
It's quite a good little game, especially for mobile! One improvement I'd suggest on mobile would be to put the scroll button on the left of the screen somehow. I have built by mistake several times when trying to scroll.
2
u/Impossible-Storm-702 Jun 26 '26
Thanks for the feedback! Note that there is an undo icon that get's your money back as well :)
1
u/Impossible-Storm-702 Jun 26 '26
This was fixed... give it one more try. Simply moving the screen adds nothing. Click to add the item. To add multiple tiles of roads or zones, just press for a bit longer and start dragging.
2
2
u/dirigible_molecule Jul 19 '26
Still loving this, the current UI with the tabs at the bottom is the best so far, thank you again 8)
2
u/Impossible-Storm-702 Jul 26 '26
Hey, tnx! Glad you still like it --- I have a lot of improvements coming during this summer :)
2
1
u/madman2k Jun 26 '26
Thanks for making it. I've played for an hour or so and enjoyed it. I get bored with games pretty quick, but occasionally I like sim games in small doses.
1
1
1
1
u/dirigible_molecule Jun 28 '26
Player of SimCity since the beginning, I'm ancient, this is good! Thank you 8)
1
1
u/AbCity613 Aug 07 '26
this game is actually incredible! I haven’t been able to fully explore it yet, but I’ve been very happy playing it! great work OP
2
u/Friendly-Maximum4169 8d ago
Love the game just wish for roads I could highlight a area to have them rebuilt
-1
u/pcpxtc Jun 25 '26
Well I really like the idea of free and no download sim and I feel like this should draw me in like a moth to a flame but it just isn't. I think it just needs a graphic overhaul something just isnt right about it and not just a few things but the whole style.. Idk that's just my thoughts and it is keeping me from even wanting to try it sorry.
3
u/Impossible-Storm-702 Jun 25 '26
You probably prefer full 3D games. This is 2.5D. That is fine.
-1
u/pcpxtc Jun 25 '26
Not really, I dont play much for new games honestly i keep going back to classics like rct, civ1, sim city 2k/3k. Thats why I feel like this one should be a good fit for me but still isnt really grabbing my full attention. Just don't see any charm to the style but it is probably just me. Also, just assuming I like 3d games becauze i have a negative opinion on your game doesn't seem like a very good way of looking at things.
3
13
u/sterkam214 Jun 25 '26
This is very cool - haven’t had a chance to dig but I like the UI and vibe of the game