Project files loaded with no issue for me in Godot 4.1.1. I tried it in an older version (3.4.4) but that failed to load. Anyways, running the scene is smooth on my machine (GTX 750, Intel i5 CPU) with 75 FPS on the display. Interpolation is a useful tool to have in the kit! The code is legible too, for what it's worth. Thanks for sharing.