itch.io

Just use a transparent shader on the game engine, that's the easiest way. 

You can get a more detailed  model version if you disable optimization before exporting.

Nice, thanks for your purchase

Unity with C#

Please, can you share a sample of the texture that you are trying to import?

Please make sure that the material is applied to the object that contains a mesh renderer.

Exported objects are models in .obj format

Drop the .obj file into unity, then the same texture and apply it to the material 

Please, can you send me a sample of your sprite sheet?

:D Wow, thank you! :D