I’ve been working on a (primarily 3D) game engine for a while, written in Rust and primarily powered by my scripting language. It’s also the technology behind Monsters and Sprites. Here’s some screenshots of a renderer I built for the project back when I was working in C++ (the scene is just a bunch of rectangular prisms with some Pixar textures on it, obviously with better art it’d be a little more impressive):

I know what you’re thinking–waay too much bloom. IIRC I was testing out an adaptive exposure shader, and took this screenshot right after turning away from a dark area.
I was also super excited about percentage closer soft shadows. You can’t tell in the picture, but I had the light set up to rotate around the scene which made watching the shadows stretch out and blur and such super fun.
And of course, the obligatory sponza SSAO test. Unfortunately I can't find any screenshots of the full renders of this scene right now.

The engine hot swaps in scripts and assets on save, and also provides feedback that can be displayed inline in external text editors:

Cut me some slack on the verbose type names and the shader API here, these things will all be improved before there's a public release. :)

And here’s a screenshot of Monsters and Sprites: