DISCLAIMER: Harvest Moon was made by Valve. This is just a bug fix, and not a new effect.

The beautiful glow on Harvest Moon has an annoying tendency to disconnect from the player's head after sustained movement in one direction.

As it turns out, the fix is quite simple.
I have attached an updated version of item_fx.pcf with the following change:
- The value of the "distance fade range" parameter of the "Movement Lock to Control Point" operator of the "unusual_fullmoon_cloudy_green_glow" particle has been changed from 70 to 0
- This has an imperceptible effect on the appearance of that unusual, and completely resolves the detaching glow issue