This game draws in 3D, which needs
WebGL. Your browser could not turn it on.
Any one of these usually fixes it:
- Open this file in Chrome, Edge or Firefox.
- Switch graphics acceleration on:
Chrome / Edge → Settings → System →
"Use graphics acceleration when available" → restart the browser.
- Update your graphics driver, then restart.
To check: open chrome://gpu and look for WebGL: Hardware accelerated.