Thanks for playing! I was just as shocked that all the shaders worked in WebGL, I was not expecting stencil buffer support (for the portal)!
There is supposed to be background music though I ran out of time to add the SFX. I'll have to look into why the background music isn't playing on Linux but I suspect the culprit is the web build. I do have a Linux machine and can look to add a native build post-jam.
Speedrunning was definitely my intention since I love games like Ghostrunner but I lost track of that with some of the level choices. If I revisit the levels post-jam, embracing momentum and removing stop-and-go sections would be a priority.