Thank you!
Yeah, the pursuer only becomes an issue when you last a certain amount of time, or play very cautiously. I think the majority of players wouldn't have their first game over to the pursuer.
As for shaders, Godotshaders.com is an excellent resource. All the custom shaders we used were at least started from sources on there. We have all the links on the game's store page. If you have any specific questions feel free to ask.