Hacker News: thealexanderlee

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Fri, 28 Aug 2026 01:15:45 +0000

good question! I'd say similar in web where ideally the agent doesn't stray too far from creating new components. I noticed that happening here as well unless you directly prompt for it.

But the design system follows a set of rules and skill files and applies them when needed!

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Thu, 27 Aug 2026 15:12:34 +0000

Hey, thanks so much for the feedback although obviously hurts a bit for wanting something I just created for fun to go into oblivion.

I totally understand your feedback though. The issue is that AI costs a lot of money under the hood, and so we needed some way to know if a user was hitting a limit. Will think about how to make that more clear upfront.

Thanks again for your feedback.

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Wed, 26 Aug 2026 23:41:50 +0000

Originally we actually started messing around with 3D assets, which turned into RCT, then we learned about Ramp Labs! Very cool project as well. There's is more "how can AI play RCT" whereas this is "how can we construct theme parks using components"

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Wed, 26 Aug 2026 23:37:15 +0000

oh wow, I'm surprised it edited the assets to look like that!

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Wed, 26 Aug 2026 23:11:32 +0000

You should be able to prompt to create your own horror assets, but it might take some time for them to build though!

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Wed, 26 Aug 2026 22:44:46 +0000

that's fair. Thanks for your feedback!

Perhaps more exciting: build a chocolate factory slide and river with a hot fudge river... haha

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Wed, 26 Aug 2026 22:43:37 +0000

oooh! Fun idea. I think this might actually work... if you upload an image + prompt it to make a theme park referencing the map.

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Wed, 26 Aug 2026 22:42:53 +0000

Hi! Thanks for trying it! Sometimes the agent can get tripped up if it doesn't have a component that matches the theme. For example, I can tell you I don't have a rocketship asset or alien asset, so it might default to something to generic in replacement. And also we have lots of pirate assets, so then it might lean toward a pirate-theme if it sees the word "island."

That said - I just noticed a bug making them overly generic. Fixing right now!

New comment by thealexanderlee in "Show HN: Build your own theme park"

thealexanderlee — Wed, 26 Aug 2026 22:40:31 +0000

that's kind of you to write, thanks for reading. Do you like RollerCoaster Tycoon too?! Anything we can make better?

Show HN: Build your own theme park

thealexanderlee — Wed, 26 Aug 2026 16:40:01 +0000

I built an agent that helps you build Rollercoaster Tycoon-influenced theme parks. You can prompt something like “Build me a cool theme park” and it’ll build a cohesive theme park with multiple worlds and connected with paths and rides.

The weird part is that I built it using the same ideas we use to make AI-generated websites follow a company’s design system.

I work as an engineer at Magic Patterns, focused on building our Design System Agent, aimed to use your existing brand, components, and conventions instead of producing something that looks like generic AI-generated UI.

By default, models tend to converge on similar-looking designs. This is part of that “vibe coded slop” feeling: the same typography treatments, shadows, cards, icons, animations, etc… My job is to figure out the right context and guardrails so that when you prompt “Build me a dashboard,” the result actually looks like your existing product.

At some point I realized those same ideas could be applied to RCT.

While in web, you might have rules about which typography, colors, spacing, and components should be used together.

In a theme park, you need rules like: rollercoasters need complete tracks, rides need entrances connected to paths, paths need to connect different areas of the park, and a pirate-themed world should actually use pirate-themed scenery.

It was interesting seeing how closely the problem of building a coherent theme park resembled the problem of building a coherent product UI. Similarly with web design, simply giving the model the right components wasn't enough.

I ended up building an eval loop where Magic Patterns would generate a park, another agent would grade it against a rubric, and then the agent would update its rules and skill files before trying again.

The rubric checked things like whether rollercoasters formed valid tracks with at least one drop, whether rides were accessible by paths, whether each world used the appropriate themed scenery, and whether the park worked as a whole.

After a lot of iterations, you can now prompt something as simple as “Build me a cool theme park.” and you should get back a fully functioning park with guests, rides, paths, rollercoasters, and themed worlds.

Best yet, you can also follow the guests, listen to their thoughts, and watch them ride the rides in RCT fashion.

Happy to answer any questions, but would love to see the parks you all create!

Comments URL: https://news.ycombinator.com/item?id=49452037

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