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solo game dev

Interview with Ken Law, the Solo Mobile Game Developer Who Replaced His 9 to 5 With a $155K Game

Roger Mendoza

• 10 min read

Most people hear “AI-powered launch system for creators” and picture another funnel diagram with 14 arrows, three paid subscriptions, and a chatbot pretending it has discovered fire. Ken Law took a more useful route. He used AI tools to get a small game shipped, put it in front of a niche he understood, and let real players tell him where it was broken.

The result was Harpagia, a mobile idle RPG built without a publisher, a marketing budget, or a giant studio lurking behind a branded hoodie. It started as a rough alpha, made its first $10 sale within days, and eventually grew from roughly $1,000 per month to more than $10,000 per month after a single Reddit post.

That is not a story about getting lucky and retiring on app-store glitter. It is a story about building something narrow, launching before it feels comfortable, and treating criticism as a distribution channel. Which is frankly more practical than buying another $97 “passive income” playbook written by someone whose main revenue stream is selling passive income playbooks.

Table of Contents

🛠️ The Setup: A Small Game Built for a Specific Kind of Player

What is Harpagia, and who is it for?

Harpagia is a free-to-play mobile idle RPG for iOS and Android. It is made for people who enjoy incremental games, especially games with the long-term progression loop associated with RuneScape.

The core idea is simple: players level skills, gather resources, collect loot, upgrade gear, and fight enemies. Much of the progress happens while they are away. They return, collect what happened, make a few meaningful choices, improve their build, and send the character back into the machinery.

That format is not trying to replace a giant console RPG. It is serving a specific appetite: the pleasure of compounding progress without having to manually tap a virtual rock for three hours straight.

Harpagia includes 16 skills. Some are straightforward, such as mining resources to improve equipment. Others are more interactive, such as archaeology, where players select tiles and make upgrades for bonuses. Combat is idle, so characters fight automatically, but equipment and abilities create room for different builds.

The important part is not that every feature is revolutionary. It is that the game gives its audience enough choices, variety, and steady rewards to keep returning.

What does the business look like behind the game?

Harpagia makes money through optional in-app purchases. Players can unlock premium features or accelerate progress, generally through purchases in the $2 to $10 range.

Ken found that purchases around $4.99 to $9.99 were usually easier for players to accept. Pricing beyond $9.99 became noticeably harder to convert. That is a useful reminder for anyone building digital products: pricing is not a math problem alone. It is a trust problem. A small purchase can feel like support or convenience. A larger one needs a much clearer reason to exist.

Over the previous year, the game averaged more than $3 in revenue per active user. Monthly revenue averaged around $13,000, adding up to more than $150,000 across the year. At its peak, revenue reached roughly $18,000 in a month.

  • Monthly active users: roughly 3,500 to 4,000
  • Daily active users: roughly 500 to 600
  • Total downloads: more than 50,000 across iOS and Android
  • Conversion rate: roughly 6%
  • Operating costs: about $500 per month
  • Paid ad spend: $0

A 6% conversion rate is especially meaningful in gaming, where a typical range can sit between 2% and 5%. But the bigger lesson is more interesting: a sustainable game business does not require millions of users. A few thousand highly engaged people can be enough.

🧱 From Big Tech to a Build That Was Actually His

What was Ken doing before he started making games?

Ken took the standard computer-science route: study at UC San Diego, enter tech after graduation, and build a career at companies most people put in their LinkedIn headline before mentioning their own name.

He spent roughly 12 years in big tech. He worked as a software engineer at Amazon and later became an engineering manager at Meta. The work was stressful, rewarding, and full of strong mentors. It also came with the illusion of stability, right up until the layoffs of 2022 made the illusion less convincing.

That shift changed his thinking. No matter how hard someone works, job security is never guaranteed. Ken wanted more control over what came next, so he began experimenting with AI-assisted development.

Why did he start with a card game instead of trying to build Harpagia immediately?

Because finishing something small is more useful than planning something massive.

At the start of 2024, Ken had not written code for more than four years. He wanted to test whether AI tools could help him build an app end to end. Rather than launch into a giant RPG, he made Big Two Wild, a simple card game based on one he and his friends had played in high school.

It took about six weeks to build. More importantly, it was intentionally small enough to ship.

That first launch taught Ken the operational parts that ambitious ideas conveniently ignore:

  • How to use AI assistance during development
  • How to build a product from concept to release
  • How app-store approval works
  • What it takes to put a real product in front of real people

This is the part many solo builders skip. They try to build their “main thing” first, then accidentally turn it into a two-year museum of unfinished Figma files. Ken built a smaller game, learned the whole pipeline, then applied those lessons to Harpagia.

🚀 The AI-Powered Launch System for Creators, Minus the Funnel Nonsense

How did Ken know when Harpagia was worth taking seriously?

He did not wait for perfect certainty. He created a threshold.

After launching Harpagia, a small group of players found it and began giving feedback. A few days later, someone spent $10 on the early alpha version. That first sale mattered because it proved that someone outside his immediate circle found enough value in the game to pay for it.

By the end of the first month, Harpagia had made about $150 in sales. By the end of month two, total sales had reached approximately $1,500. That did not replace a Meta salary, obviously. But it was evidence.

Ken set a clear rule: if the game reached $10,000 per month organically, he would leave his job and work on it full time.

That is a much better system than quitting because a motivational quote hit unusually hard at 1:17 a.m. The target was concrete, tied to actual demand, and high enough to prove the business had real traction.

What does that launch system look like in practical terms?

For solo builders, this is a useful model for launching with AI tools without pretending AI handles the hard parts. The tools speed up production. They do not manufacture retention, trust, or a reason for anyone to care.

  1. Choose a niche you understand. Ken knew gaming and understood the incremental-game audience.
  2. Start with a deliberately small project. His first card game was a shipping exercise, not a moonshot.
  3. Use AI to reduce build friction. AI helped him return to coding, brainstorm, and handle small design tasks.
  4. Launch a rough version on a deadline. Harpagia went live after six months, even though the bigger vision was nowhere near finished.
  5. Get feedback from potential customers. Friends and family may be nice. Nice is not a product signal.
  6. Prioritize retention before monetization. Make something people want to keep using before aggressively optimizing what they pay for.
  7. Set an evidence-based threshold for going full time. Revenue goals make the leap less theatrical and more deliberate.

It is not an AI funnel builder in the usual sense. It is an actual build loop: create, ship, learn, improve, repeat. The least glamorous loop is usually the one that works.

📣 Reddit, Criticism, and the Weirdly Effective Zero-Dollar Marketing Plan

How did Harpagia grow from around $1,000 to $10,000 a month?

Six months after launch, Ken made his first Reddit post about Harpagia. The response was heavily critical. It also put the game in front of thousands of people.

Revenue jumped from about $1,000 per month to more than $10,000 per month almost overnight. That one post hit the threshold Ken had set, and he left Meta that same month.

It is tempting to boil this down to “all publicity is good publicity.” That is too neat. Bad attention can absolutely damage a weak product. What worked here was that criticism created discussion, discussion created visibility, and enough people were interested to try the game for themselves.

The game was rough around the edges at the time. That did not stop the post from working. In fact, the roughness gave people things to react to, debate, and critique. The internet, as always, was thrilled to help.

What did Ken post on Reddit?

The early posts used screenshots and a straightforward explanation of the game. Ken also shared metrics around how free-to-play the experience was, addressing an obvious concern for mobile-game players: whether the game would be enjoyable without being pushed into endless purchases.

Reddit became Harpagia’s primary marketing channel. Results were not perfectly consistent, but nearly every post produced a meaningful jump in new players.

There was one constraint: many relevant subreddits limit promotion to about once a month. Ken responded by posting only when he had meaningful updates, often every few months rather than forcing content into communities that did not ask for it.

That restraint matters. A community is not a free billboard with moderators. Treat it like a room full of people with excellent pattern recognition for self-promotion.

What can creators borrow from this Reddit strategy?

  • Show the actual product. Screenshots and specifics beat vague “building in public” fog.
  • Address the audience’s real objections. Ken clarified the free-to-play experience because that concern mattered to players.
  • Post around real updates. Give people a reason to discuss the build beyond “it still exists.”
  • Expect criticism. Use useful feedback to improve the product instead of treating every negative comment like a federal investigation.
  • Follow community rules. Distribution that gets a builder banned is not a strategy.

For a solo builder tech stack, this is the cheaper alternative to trying to automate funnel with AI before there is anything worth funneling people toward. First earn attention. Then keep it.

🎮 Why Small Games Can Still Be Real Businesses

Is there still room for solo developers in gaming?

Yes, but the opportunity is not necessarily building the next Clash of Clans or hoping to recreate a once-in-a-decade viral hit. The gaming industry is enormous, but a solo developer does not need a mass-market outcome to build a meaningful business.

Ken’s experience changed his own expectations. He did not expect a few hundred active users to generate more than $100,000 in annual revenue. Yet a small audience that genuinely likes a product, keeps returning, and occasionally pays for optional upgrades can support a business.

This is the niche-business argument in its least glamorous, most useful form: find a group with a real preference, build for it well, and avoid measuring success only against companies with stadium-sized marketing budgets.

What is the biggest misconception about building a game?

The misconception is that scale is the only thing that matters. Developers often assume they need hundreds of thousands or millions of players before revenue becomes meaningful.

Harpagia demonstrates a different equation. With roughly 3,500 to 4,000 monthly active users, an average revenue contribution above $3 per active user, controlled operating expenses, and no advertising costs, a small game can be financially serious.

That does not mean every niche game will work. It means the target does not have to be global dominance. It can be a product that a defined group cares about enough to keep using.

⚙️ Ken’s Lightweight No-Code Startup Tools and Development Stack

What tools did Ken use to build and run Harpagia?

Harpagia runs on a deliberately lightweight stack. The point is not to collect tools like trading cards. The point is to use enough infrastructure to ship and maintain the product without creating an administrative side quest.

  • Cursor: coding environment for building the product
  • ChatGPT: brainstorming and icon touch-ups
  • React Native: frontend development
  • Firebase: backend, authentication, and analytics
  • Discord Nitro: community management
  • Vercel: web hosting
  • Unity Asset Store and Game Dev Market: pre-made game assets that save time on art production
  • Fiverr and Upwork: freelancers for screenshots, icons, and videos

Calling every part of this “no-code startup tools” would be a stretch because Ken is building in code. But the underlying lesson applies to both technical and nontechnical creators: buy or outsource the work that is not the core of the product, especially when it prevents shipping.

Ken used purchased assets and freelance help for visual production so he could focus on development. That is a sane trade. Solo does not have to mean doing every pixel, screenshot, and promotional asset personally while slowly becoming a spreadsheet with anxiety.

🧠 The Real Talk: Ship the Version That Makes You Slightly Uncomfortable

What advice would Ken give himself before starting?

Build something understood well, then get real feedback as early as possible from the people who might actually use it.

Ken’s best decision was forcing a launch after six months regardless of whether Harpagia matched his full vision. It did not. But releasing early made the game better because real players revealed what mattered, what did not, and where the experience needed work.

That is the durable lesson behind this whole build. Product improvement is not something that happens in private through heroic polishing. It happens when the product meets reality.

If version one, version two, or even version five does not create a little embarrassment, the launch may be happening too late. Perfection is often just procrastination with better typography.

What should a solo builder prioritize first?

Retention.

Ken did not obsess over monetization in the beginning. He focused on making a game people wanted to keep playing. That sequence matters because monetizing a product nobody returns to is just optimizing a leak.

For creators building apps, games, or any compact digital product, the AI-powered launch system for creators should start with one question: Will a real person come back?

AI can accelerate a prototype. It can help brainstorm, edit an icon, write a rough implementation, or lower the barrier to making a first release. It cannot substitute for knowing a niche, listening to customers, or giving them a reason to return tomorrow.

Ken’s path was simple enough to test tonight: choose something familiar, make the smallest shippable version, get it in front of strangers, and use their reactions to decide what happens next. Remix the stack, swap the channel, change the product. Keep the loop.

❓ Frequently Asked Questions

How much revenue does Harpagia generate?

Harpagia averaged around $13,000 in monthly revenue over the past year, totaling more than $150,000. Its reported peak monthly revenue was roughly $18,000.

Did Ken use paid advertising to grow Harpagia?

No. Ken reported spending $0 on ads. Reddit was his primary growth channel, with product posts creating substantial spikes in new players and revenue.

What caused Harpagia to reach $10,000 per month?

A Reddit post made about six months after launch generated significant discussion and criticism, putting the game in front of thousands of potential players. Revenue rose from roughly $1,000 per month to more than $10,000 per month.

What technology does Harpagia use?

Ken’s stack includes Cursor, ChatGPT, React Native, Firebase, Discord Nitro, and Vercel. He also uses game asset marketplaces and freelancers for selected visual work.

What is the most important launch lesson from Ken’s story?

Launch before the product feels finished, then seek feedback from potential customers rather than relying on friends and family. Ken also recommends focusing on retention before pushing monetization.

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