I was wondering if there was a way to add an effect to all layers but without them overlapping. currently if i add an effect to each one of my layers, they stack and it starts to strengthen the effect significantly. is there a way to add an effect OVER all layers without them stacking?
So you’d like the one effect to be applied to all the layers once, rather than each layer because it appears to multiply or intensify the effect? That sounds like a post-processing shader, which GDevelop can’t do. Each shader (layer effect) is applied to the objects on a layer, not all objects on screen. I can only see the effect being possible if you flatten the layers, and have all objects on one layer.
Maybe put it in as a feature request?