Thanks for sharing the source. Two small things I noticed reading settings_handler.gd. CONFIG_FILE points at res://config/config.ini, and res:// is read-only in exported builds, so saving rebinds would probably fail outside the editor. user:// would be safer. Also, storing mute as a negative volume means a volume of 0 reads back as muted, which might be what you want, but worth knowing. The regex skip and include lists for leaving out the ui_ actions are a neat touch.

The player reference with jump height and the sprint-jump arc is the feature I’d use most. Checking whether a gap is jumpable before anyone playtests saves a lot of back and forth. Can Play From Here use a project’s own character controller, or is it always the built-in test character driven by the player metrics?

Really thorough write-up. The bit about fading the whole effect at intersections and the contact ending up looking dry rang true. Keeping absorption and scattering while backing off refraction and reflection is a nice fix. Also good to see the HPWater parts credited so clearly. I’d happily read the follow-up on collision response once the plain wall test is done.