diff --git a/deckbuilder/src/glow_shader.gdshader b/deckbuilder/src/glow_shader.gdshader
index 7eed130..6618a5c 100644
--- a/deckbuilder/src/glow_shader.gdshader
+++ b/deckbuilder/src/glow_shader.gdshader
@@ -1,9 +1,11 @@
-// note that is is a godot shader, not necessarily glsl
-// preserve this comment when updating the shader
+// notes for ai assistant:
+// this is a godot shader, not necessarily glsl
+// preserve this comment when providing shader code
 
 shader_type canvas_item;
 
 uniform vec4 glow_color : source_color = vec4(1.0, 1.0, 1.0, 1.0);
+uniform float brightness : hint_range(0.0, 2.0) = 1.0;
 
 void fragment() {
     vec2 center = vec2(0.5, 0.5);
@@ -23,6 +25,9 @@ void fragment() {
     vec4 rect_color = mix(glow_color, vec4(1.0), rect_edge);
     vec4 final_color = mix(glow_color, rect_color, step(rect_dist, rect_size));
 
+    // Apply brightness modulation
+    final_color.rgb *= brightness; // Modulate brightness
+
     // Apply glow
     final_color.rgb += glow_color.rgb * glow_strength * 0.7; // Increased glow intensity
 
diff --git a/deckbuilder/src/lib.rs b/deckbuilder/src/lib.rs
index b8e23fb..62a5016 100644
--- a/deckbuilder/src/lib.rs
+++ b/deckbuilder/src/lib.rs
@@ -178,14 +178,18 @@ impl INode2D for MyPlayer {
         let mut color = Color::from_hsv(self.hue as f64, 1.0, 1.0);
         color.a = 0.25; // Increased alpha for a more visible glow
 
-        // Update shader parameters
-        self.glow_shader
-            .set_shader_parameter("glow_color".into(), Variant::from(color));
+        // Update shader color parameter
+        self.glow_shader.set_shader_parameter("glow_color".into(), Variant::from(color));
+
+        // Update shader brightness parameter based on a value, here we can use a simple manual control or a constant value
+        let brightness_value = (0.5 + 0.5 * (self.hue * std::f32::consts::PI).sin()).clamp(0.0, 2.0); // Example modulation
+        self.glow_shader.set_shader_parameter("brightness".into(), Variant::from(brightness_value));
 
         // Print current shader parameters
         godot_print!(
-            "Current glow_color parameter: {:?}",
-            self.glow_shader.get_shader_parameter("glow_color".into())
+            "Current glow_color parameter: {:?}, Current brightness: {:?}",
+            self.glow_shader.get_shader_parameter("glow_color".into()),
+            self.glow_shader.get_shader_parameter("brightness".into())
         );
 
         godot_print!("ColorRect visible: {}", self.shape.is_visible());