19 Games And 16 Versions Later: Lessons From An AI Coding Agent Project

🔍 Read the full analysis: 19 Games And 16 Versions Later: Lessons From An AI Coding Agent Project on ThorstenMeyerAI.com

Before you orderOffer from Amazon

Get hardware and tech essentials delivered free with Prime

• Fast, free delivery on millions of items
• Prime Video, Amazon Music and more included
• Member-only deals all year

Start your free Prime trial →Free trial for eligible customers · Cancel anytime

As an affiliate, we earn on qualifying purchases.Hide

Developer Thorsten Meyer says he built and released a free web app for tracking a German partial-retirement schedule in five days, working with Claude Opus 5.5 as a coding agent. What began on September 28 as a request for a one-minute animated film expanded into a public countdown site with 19 3D games, multilingual audio and tools for planning time off, according to Meyer’s October 13 account.

The app, called Altersteilzeit, is designed for people using Germany’s block model of partial retirement. Users enter the start date of either their active work phase or their time away from work, select a schedule from 1:1 to 5:5, and add their federal state and leave. Meyer says the app then calculates remaining working days, excluding weekends and state public holidays.

The site combines a daily countdown with a short film and games based on the user’s timeline. The daily view includes milestones and a saying of the day, and can display continuously on a tablet, export dates to a calendar or produce a printable countdown. Other features include a bridge-day finder, badges and a team countdown. Meyer’s description says the game area contains 19 ways to play, with calendar time shaping levels and game mechanics.

Meyer reports that the project took 16 versions and involved 24 commits co-authored by the agent. The work included about 18,000 lines of JavaScript and Python, 15 test scripts, and 1,224 voice clips across 12 languages, according to his account. He says he gave instructions, reviewed the results, chose creative details and approved releases. These figures and descriptions come from Meyer; the source material does not include an independent technical audit.

What the Five-Day Build Shows

The project offers a specific account of how an AI coding agent can contribute to a small software release: not just generating code, but helping coordinate testing, translations, audio production and deployment. Meyer’s description suggests the pace came from repeatedly giving the agent a defined task, reviewing its output and deciding what to build next. The reported schedule is a project account, not evidence that similar results can be expected for other products.

It also highlights the work that Meyer says remained with him. He chose the app’s premise and tone, selected voices and dialects, determined how narration should relate to captions, and approved the public release. Those decisions shaped the product in ways that are not captured by a count of commits or lines of code. The distinction matters to readers evaluating coding agents: the account describes a human directing and checking the work, rather than a tool independently deciding what to make.

For users, the app’s stated privacy design is another relevant detail. Meyer says it has no accounts, cookies or tracking and calculates dates in the browser. Shared dates are placed after the “#” in a web address, which he says is not sent to a server in a standard request. The source describes the design but does not provide a separate privacy review.

From Film Request to Countdown Site

Altersteilzeit is a form of partial retirement. In the block model described by Meyer, a person works their usual schedule during an active phase and is then released from work for a matching period. A 4:4 arrangement, for example, means four years in each phase. The app turns that long interval into a count of working days and milestones.

Meyer says his initial request on Monday, September 28, was for a short animated film about the two phases. Over the next several days, he added date calculations, game prototypes, a daily view, language support, audio and legal pages. His timeline says the site was online by the evening of the first day, with further features added through Friday, October 2. He describes the final release as including seven languages and five German dialects, while also reporting audio production in 12 languages; the account does not explain how those language counts map to every part of the app.

“The interesting part is not how much an AI agent can build, but what was still left for me to do.”

— Thorsten Meyer

What the Project Account Cannot Verify

The available source is Meyer’s first-person account, not an independent assessment of the app or the agent’s contribution. It does not identify the coding agent’s exact configuration, provide a breakdown of time spent by Meyer and the agent, or show test results beyond the stated number of test scripts. It is also unclear how the reported 16 versions relate to the 24 commits.

The source describes the app as free and says its calculations happen in the browser, but it does not include an external check of the date calculations, privacy behavior, accessibility or performance. The reported counts for games and languages also appear in different contexts: Meyer says there are 19 ways to play, while the timeline mentions earlier additions in batches. The account does not give a version-by-version inventory to reconcile those details.

The App After Its Initial Release

Meyer’s account does not name a scheduled next release, additional feature or independent evaluation. The app was already public by October 2, he says, and his October 13 article recounts how it was built. Readers can expect further developments only if Meyer announces them; the source does not set out a roadmap.

The next useful evidence would be an updated product record showing which features and languages are currently available, alongside independent checks of the working-day calculations and privacy claims. Until then, the project’s scope, timeline and technical figures should be understood as reported by its creator, with the agent’s role described by Meyer rather than externally measured.

Key Questions

What is the Altersteilzeit app?

It is a free web app that Meyer says tracks the working days remaining in a German partial-retirement plan. Users enter dates, choose a work-and-release schedule, and can use countdown, film and game features.

How long did the project take?

Meyer says development ran from September 28 to October 2, 2026, with the site online by the first evening and later features added over the next four days.

What did the AI coding agent do?

According to Meyer, Claude Opus 5.5 helped with engineering, testing, translations, voice clips, sound effects and deployment. Meyer says he supplied direction, made product and creative choices, reviewed the work and approved releases.

Does the app collect personal data?

Meyer says the app has no accounts, cookies or tracking and performs calculations in the browser. Those are claims in his project account; the source does not include an independent privacy audit.

Are the reported development figures independently verified?

No independent verification is included in the source. The counts of versions, commits, games, lines of code, test scripts and audio clips are figures reported by Meyer.

Source: ThorstenMeyerAI.com