Can I use LÖVR without a VR headset?

Yes, LÖVR will automatically use a fake headset system that you can control with your keyboard/mouse if there isn't any VR hardware detected.

You can also set the t.modules.headset flag to false in lovr.conf to disable VR completely and develop a traditional 3D desktop application.

Keep in mind that LÖVR is primarily designed for creating VR experiences, which have their own design considerations. Practically this means that LÖVR does not prioritize features common in other engines like advanced control over the desktop window, mouse input, joystick support, and touchscreens. There are some plugins available that help bridge this gap.

Is there any way to access keyboard/mouse input?

Yes, there are lovr.keypressed, lovr.keyreleased, and lovr.textinput callbacks. For mouse input, see lovr-mouse on the Libraries page.

Is there autocomplete for VS Code?

See this gist.

Does LÖVR support AR?

LÖVR does not currently support Magic Leap, HoloLens, or "magic window" style AR on phones. There are some ways to experiment with AR on LÖVR using passthrough devices like the North Star or SteamVR's Room View 3D. LÖVR's direction is guided by the community, and as more AR hardware comes out there will likely be future demand and development on AR support.