itch.io

Can confirm the same happened to me from two separate email accounts. I was trying to contact them to get a refund from an accidental double purchase I made on something half a year ago but it's a bit hard when the email server isn't even receiving the email. It seems like it's misconfigured to not receive emails but it seems it's still sending them because I'm getting receipts just fine.

GLTF and other 3D file formats are usually for meshes and 3D objects and not particle effects which are made through emitters and sprites with some shaders and other effects and physics.

A plugin for blender that directly uses the pixelpart effects might be possible but I don't know if the userbase for it would be large enough to justify it's development. It would only realistically be usable for videos made in blender and it wouldn't be able to be incorporated in those 3D models as an output for a game or anything. The 3D file formats are generally at most capable of handling the mesh data, texture data, and animations.