Thanks for testing it!
Yeah, there is definitely something wrong here, the good news is I think I know what. In the main update loop, I calculate the delta time between frames and use this for all the physics and animation updates. The only reason I can think this is so slow despite the high frame rate, is the calculated delta time is a lot lower than it should be.
I have a new build, if you could test it out, I would really appreciate it.
Hillslide.pdx.zip (5.0 MB)