Yeah its a noted issue for the web version, still unsure how to preload vfx in godot before loading screens pop up but its a learning experience.
Thanks for completing the game despite the lag and difficulty, glad you enjoyed it!
I think I saw a YouTube video of another dev have the same issue with their Godot game. Their solution was to have a black screen that said "Compiling shaders", but what was actually happening in the background was all the vfx were just going off until they were cached. I think this was before Godot introduced shader compilation though. Not sure if they've added an official solution since then, but it's just an idea hahah