immortalxgr

For openness and simplicity look no further. LOVR is written in C with a hand-built Vulkan engine, and you script your games/apps in Lua. It's that simple. No app-stores, no subscriptions, no web technologies/browsers. You can have a VR "Hello World" in 3 lines of code.

I've been using it for a couple years now and I can't stress enough how easily you can get started for VR, especially compared to "full" engines. And it might be tailored for VR but it's absolutely fine for general 2D/3D as well.