I think what I struggled with the must is understanding that you have to use the potion on a shadow you are not in contact with. Maybe a more guided tutorial like combine 2,1,1 potions and apply in this tile. But that depends on how much you want to guide the player.
Unsure if there is only the tutorial level or I just could not figure out how to proceed. Either way I think the idea is very cool and it works so def looking forward for more.
Nice job, the game looks promising. I really like the art style.
Just sharing in case you did not know. I faced the same issue with stuttering due to shader loading. What I did to prevent that is adding a node to the level scene using that same shader but hidden. That way the shader is also loaded when the level is loaded. It will take slightly longer to load but you will not experience stutters while playing.
