A free model that runs on a laptop. Fast, private, and sloppy.
Worth using only when something checks its work.
Qwen3 30B, an open model. Nothing leaves the machine and nothing is billed. A 40-word list came back almost instantly.
A dictionary, a test suite, a rule scan. Of the 30 distinct words, one was not a real word; ten of the 40 were repeats.
Qwen reads text only. It cannot see a screenshot, so how a game looks and feels is judged by a person or a bigger model.
Nothing Qwen writes goes live on the strength of the model alone.
The checker is the product. The model is the cheap part.
What it is. Qwen3 30B is an open-weight model running through Ollama on the studio laptop. It has 30 billion parameters but uses about 3 billion for each word, so it answers at small-model speed. In this setup it can hold about 32,000 tokens at once (roughly 24,000 words), counting the instructions, the code it reads, and what it writes.
What the first test showed. Asked for 40 basketball words for a word game, it answered in 1.7 seconds, at about 127 tokens a second. The game's dictionary accepted 29 of its 30 distinct words. But a quarter of the list was repeats, and several words were only loosely on theme. Fast and free, not careful.
What that means. Use it for repetitive work that a program can grade: lists, test cases, one small file at a time against written rules. Don't hand it a whole game at once, and don't let it review code on its own. Instructions written for a large model also tend to work worse on a small one, so anything Qwen reads has to be written for Qwen.
The rules, the drawing and the controls running below are Qwen's code, exactly as it wrote them. The page around them is ours, because Qwen's own page never started the game. Click the board, then use the arrow keys or WASD. On a phone, swipe or use the buttons.
Open full screen →Play it on GAMEBOYO →Play BLOCKS by Qwen →Qwen's own page, untouched →
Watch the food. It only ever appears in two squares, taking turns. That is a bug in Qwen's rules that all 17 tests missed: it never moves its random number forward, so every new piece of food comes from the same two draws. We left it in.
The studio's games follow house rules: small files, a pure rules engine with tests, graphics drawn in code, no downloaded assets, sound off until you turn it on, no motion when a device asks for less. The experiment gives Qwen one short file of those rules, then asks it to build a tiny game one file at a time. Tests and a rule scan grade every file; a person grades the screenshots.
Useful for logic only.
Qwen wrote the rules, the drawing and the controls, and each passed its tests with no human edits. It could not wire them into a working page in three tries. The game never started outside reduced-motion mode, and the touch buttons ignored a house rule even after the failing check was shown back to it.
The test game is Snake on a 20 by 20 grid. Its state is a handful of whole numbers, so the rules can be tested exactly: where the head is after a move, growing when it eats, dying at a wall. We picked it over Pong, whose bouncing maths only tests to a tolerance, and because Snake can stay fully playable with motion off by moving one step per key press.
Everything that grades Qwen is written before Qwen sees anything: a one-page spec, 17 tests, a browser check, and a scan for house-rule breaks. Qwen never writes its own tests, because a model that writes the code and the test together tends to test what it built, not what was asked for. Each lesson gets one try and two retries. A retry only sees the lines that failed.
| Lesson | Qwen writes | It passes when | What happened |
|---|---|---|---|
| 1 · Rules | The game logic, with no page or timer code | 11 of 11 tests pass; the rule scan finds nothing | Passed on try 2. Try 1 forgot to export two constants; shown only that error, it fixed it. 32 s. |
| 2 · Drawing | The board, drawn with rectangles and paths only | 3 of 3 tests pass; no images or downloads | Passed first try. 21 s. |
| 3 · Controls | Arrow keys, WASD, and swipes turned into moves | 3 of 3 tests pass | Passed first try. 27 s. |
| 4 · The page | The game loop, sound switch, and page | Browser check passes on phone and desktop; screenshots look right | Failed all 3 tries. Space never started the game; touch buttons used clicks instead of pointer events. 63–119 s a try. |
The verdict was fixed before the run, so the bar could not move.
Plan by Fable, reviewed before the run. Two problems in the setup, not in Qwen, were caught and fixed before any Qwen output existed, and are logged in the plan. One gap was ours: the page lesson showed Qwen the controls function's name but not what it expects, which explains one of its page bugs but not the two that failed it. Settings: Ollama 0.33.3, thinking on, temperature 0.6, seed 42. One game, one run: a data point, not a verdict on the model.
| Date | Test | Result | Status |
|---|---|---|---|
| 13 Sep 2026 | 40 themed words for a word game, graded by the game's dictionary | 1.7 s · 127 tok/s · 10 repeats · 29 / 30 real words | Done |
| 14 Sep 2026 | Build Snake from the style file, four lessons, graded by 17 tests and a browser check | 3 of 4 lessons passed · page failed 3 tries · useful for logic only | Done |
| 14 Sep 2026 | Played Qwen's Snake logic inside our page | Playable. Food only spawns in two squares, a rules bug the 17 tests did not catch | Done |
| 14 Sep 2026 | Rerun, 3 seeds each: fix the food bug from a failing test | 3 of 3 fixed it on the first try | Done |
| 14 Sep 2026 | Rerun, 3 seeds: build the page again, this time told exactly what the controls function expects | 1 of 3 passed the checks, and that page barely plays (tiny board, taps ignored). Page wiring moves to our GAMEBOYO console; Qwen writes cartridge logic | Done |
| 14 Sep 2026 | BLOCKS, a falling-block game, 3 seeds: pieces and rules, graded by 56 tests and 20,000 random-input frames | 3 of 3 passed. Checking against our correct version afterwards found a real bug the tests missed in 2 of 3 (the preview piece gets skipped) | Done |
| 14 Sep 2026 | BLOCKS cartridge for GAMEBOYO, 3 seeds | 0 of 3 when our prompt left out the board size and piece helpers; 3 of 3 once it included them. The seed-42 version is playable on GAMEBOYO, bugs and all | Done |
Numbers are from single runs on one laptop. They show what happened, not a benchmark.