diff --git a/lesson#24 - Observer Design Pattern/ourGame/.gitignore b/lesson#24 - Observer Design Pattern/ourGame/.gitignore
deleted file mode 100644
index b2c8b49..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/.gitignore	
+++ /dev/null
@@ -1,15 +0,0 @@
-.dub
-docs.json
-__dummy.html
-docs/
-/ourgame
-ourgame.so
-ourgame.dylib
-ourgame.dll
-ourgame.a
-ourgame.lib
-ourgame-test-*
-*.exe
-*.o
-*.obj
-*.lst
diff --git a/lesson#24 - Observer Design Pattern/ourGame/dub.json b/lesson#24 - Observer Design Pattern/ourGame/dub.json
deleted file mode 100644
index fb77399..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/dub.json	
+++ /dev/null
@@ -1,15 +0,0 @@
-{
-	"authors": [
-		"rillk500"
-	],
-	"copyright": "no copyright",
-	"dependencies": {
-		"raylib-d": "~>3.0.3"
-	},
-	"description": "2D game",
-	"libs": [
-		"raylib"
-	],
-	"license": "no license",
-	"name": "ourgame"
-}
diff --git a/lesson#24 - Observer Design Pattern/ourGame/dub.selections.json b/lesson#24 - Observer Design Pattern/ourGame/dub.selections.json
deleted file mode 100644
index 6c4a00d..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/dub.selections.json	
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-	"fileVersion": 1,
-	"versions": {
-		"ddmp": "0.0.1-0.dev.3",
-		"fluent-asserts": "0.13.3",
-		"libdparse": "0.14.0",
-		"raylib-d": "3.0.3",
-		"stdx-allocator": "2.77.5"
-	}
-}
diff --git a/lesson#24 - Observer Design Pattern/ourGame/source/app.d b/lesson#24 - Observer Design Pattern/ourGame/source/app.d
deleted file mode 100644
index d917685..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/source/app.d	
+++ /dev/null
@@ -1,44 +0,0 @@
-import data;
-import gstatemanager;
-
-import menu;
-import play;
-
-void main() {
-	/*// init
-    InitWindow(windowWidth, windowHeight, "Mission X");
-    scope(exit) CloseWindow();
-
-	// set frames per second
-    SetTargetFPS(60);
-
-    while(!WindowShouldClose()) {
-        // process events
-
-        // update
-		// calling the dummy function
-		GStateManager.getInstance().hello_world();
-
-        // render
-        BeginDrawing();
-		scope(exit) EndDrawing();
-
-        ClearBackground(Colors.WHITE);
-		// .. draw ..
-    }*/
-}
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/lesson#24 - Observer Design Pattern/ourGame/source/data.d b/lesson#24 - Observer Design Pattern/ourGame/source/data.d
deleted file mode 100644
index 031a1a6..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/source/data.d	
+++ /dev/null
@@ -1,15 +0,0 @@
-module data;
-
-// mostly used libraries
-public import raylib;
-public import std.stdio: writeln, write;
-
-// window dimensions
-immutable windowWidth = 720;
-immutable windowHeight = 640;
-
-// state interface
-interface IState {
-	void run();
-}
-
diff --git a/lesson#24 - Observer Design Pattern/ourGame/source/gstatemanager.d b/lesson#24 - Observer Design Pattern/ourGame/source/gstatemanager.d
deleted file mode 100644
index a83a6ae..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/source/gstatemanager.d	
+++ /dev/null
@@ -1,47 +0,0 @@
-import data;
-
-class GStateManager {
-    // private class instance
-    private static GStateManager instance;
-    
-    // IState interface
-    private IState state;
-
-    // private constructor
-    private this() { }
-
-    // return the instance; create the instance, if it wasn't created yet
-    static GStateManager getInstance() {
-        if(instance is null) {
-            instance = new GStateManager();
-        }
-
-        return instance;
-    }
-
-    // set game state
-    void setState(IState state) {
-        this.state = state;
-    }
-
-    // execute the current game state code
-    void execute() {
-        if(state is null) {
-            return;
-        }
-
-        state.run();
-    }
-}
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/lesson#24 - Observer Design Pattern/ourGame/source/menu.d b/lesson#24 - Observer Design Pattern/ourGame/source/menu.d
deleted file mode 100644
index 3484d62..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/source/menu.d	
+++ /dev/null
@@ -1,12 +0,0 @@
-module menu;
-
-import data;
-
-class Menu: IState {
-	this() {}
-
-	// inherited from IState interface
-	void run() {
-		writeln("*** menu state ***");
-	}
-}
\ No newline at end of file
diff --git a/lesson#24 - Observer Design Pattern/ourGame/source/play.d b/lesson#24 - Observer Design Pattern/ourGame/source/play.d
deleted file mode 100644
index 054cb02..0000000
--- a/lesson#24 - Observer Design Pattern/ourGame/source/play.d	
+++ /dev/null
@@ -1,12 +0,0 @@
-module play;
-
-import data;
-
-class Play: IState {
-	this() {}
-
-	// inherited from IState interface
-	void run() {
-		writeln("*** play state ***");
-	}
-}
\ No newline at end of file
diff --git a/lesson#24 - Observer Design Pattern/slides/ObserverDiagram2.png b/lesson#24 - Observer Design Pattern/slides/ObserverDiagram2.png
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diff --git a/lesson#24 - Observer Design Pattern/slides/ObserverExample.png b/lesson#24 - Observer Design Pattern/slides/ObserverExample.png
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