Interesting idea! Just to note that there’s an issue on your server - I connect, die immediately,
(You died from FALL) - this is a bug in Glowstone I’ve been meaning to fix, just submitted a pull request here: https://github.com/GlowstoneMC/Glowstone/pull/469 (also applied the fix in Glowstone Light 5 and pushed to netcraft.herokuapp.com).
and are stuck in a block. Wew!
For now you have to dig your way out it is an adventure :). But it seems to be a race condition or related to timing, I haven’t seen this issue locally but I do see it now, logged a bug to investigate later https://github.com/satoshinm/WebSandboxMC/issues/50.
Also, I can’t seem to turn my view. Browser is Vivaldi.
Testing with Vivaldi 1.9.818.44, I can replicate this problem. The issue is Vivaldi does not support the Pointer Lock API: https://forum.vivaldi.net/topic/9092/support-for-mouse-cursor-capture/2 - these browsers support it (most modern browsers): http://caniuse.com/#feat=pointerlock. Without it its not possible to reliably capture the mouse to implement mouse look / free look. However, Vivaldi browser does support the HTML5 Gamepad API so if you have a controller that works on http://html5gamepad.com you can use that, or as a last resort, the keyboard’s arrow keys can be used to move the camera.
I have not tested much with lesser known browsers, but curiously, testing now with the Brave browser I also see it doesn’t support pointer lock either. And both these browsers are based on Chrome’s Blink layout engine, yet Chrome itself supports Pointer Lock just fine. I’ll see what I can do to better support these niche browsers but my main targets for best support are Chrome, Firefox, and Safari.