Added missing blood shader

game/shaders/invert.gdshader

@@ -0,0 +1,9 @@
+shader_type canvas_item;
+
+uniform sampler2D screen_texture : hint_screen_texture, filter_nearest;
+
+void fragment() {
+    vec4 screen_color = texture(screen_texture, SCREEN_UV);
+    vec3 inverted_color = 1.0 - screen_color.rgb;
+    COLOR.rgb = vec3(inverted_color);
+}

game/shaders/invert.gdshader.uid

@@ -0,0 +1 @@
+uid://cdakbomof1cc6