Standalone build
The whole engine in one folder. No installer, no account, and no internet after the download — unzip it and double-click. 33 levels, with a picker so you can jump to any of them.
Windows marks every zip that came from the internet. Before extracting, right-click the zip → Properties → tick Unblock → OK.
Skipping this is the single most common reason the launcher opens and then does nothing at all.
Right-click → Extract All. Extract it somewhere ordinary like your Desktop or Downloads — avoid Program Files, which needs admin rights to write into.
Inside the extracted jn-engine-win64 folder. A small window opens — pick a level, press Play. Closing the game brings the picker back so you can pick another.
No damage is ticked by default, so nothing can kill you while you're looking around. Untick it if you want the hazards live.
Press H in-game for this list at any time. It also appears by itself for ten seconds each time a level loads.
All 25 story levels and all 8 VR challenges from Boy Genius, reachable from the picker or the in-game menu. The VR levels have their geometry for the first time in this build — they previously loaded their object placements and then found nothing to stand on.
This is a QA build for shaking out crashes and rendering faults, not a playthrough — enemies, pickups and story progression are all partial.
Almost always the unblock step. Delete the extracted folder, right-click the zip → Properties → Unblock, then extract again.
If it still does nothing, your machine may block PowerShell scripts by policy. The launcher handles that itself — it falls back to the in-game menu, where you choose a level with the arrow keys and Enter. You can also run jnengine.exe directly from inside the folder.
Expected: the build isn't code-signed, because a signing certificate costs money this project doesn't have. Click More info → Run anyway. If you'd rather verify it first, the zip's SHA-256 is on the release page and every line of the engine is on GitHub.
Windows 7 only. Install the Visual C++ 2015–2022 Redistributable (x64), or Windows Update's Universal C Runtime package (KB2999226).
The engine needs OpenGL 3.3, which means any DX10-class GPU or newer. On laptops with two GPUs, Windows sometimes hands it the weaker integrated one: right-click jnengine.exe → Run with graphics processor, or set it to High performance in your graphics control panel.
The console window holds the reason. Run PLAY.bat and read the last few lines before it exits.
Known and harmless. big_3, big_4 and big_6 aren't in the extracted asset set yet, so the log warns about them on every start.
Bug reports are the whole point of this build, and as of QA6 you can file one without leaving the game — pointing at the thing beats describing it. Press B to turn on QA mode: the camera stops following the mouse and the cursor picks objects instead, highlighting whatever it is over. You can still walk around.
jn-qa-report.json next to the game and copies it to your clipboardSaved cards stack up in the top-right corner. They only live for as long as the game is open, so press X before you quit — then email the report to [email protected], or post it in the JN crew Discord.
For anything a card cannot capture — a crash, a hang, bad performance — what helps most is: your CPU, GPU and Windows version · which level you were in · what you did, what you expected, and what happened instead · and the console text.