diff --git a/.gitignore b/.gitignore
index 9bf26cb..a638545 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,7 @@
 *.a
 *.lib
 *-test-*
+*_test
 *.exe
 *.pdb
 *.o
diff --git a/dub.sdl b/dub.sdl
index d9c2fa6..85ad1af 100644
--- a/dub.sdl
+++ b/dub.sdl
@@ -6,5 +6,7 @@ license "LGPL-3.0"
 targetType "none"
 dependency "gameengine:engine" version="*"
 dependency "gameengine:rsdl" version="*"
+dependency "gameengine:test" version="*"
 subPackage "engine"
-subPackage "renderer/rsdl"
\ No newline at end of file
+subPackage "renderer/rsdl"
+subPackage "test"
\ No newline at end of file
diff --git a/engine/dub.sdl b/engine/dub.sdl
index a205d97..785a1fd 100644
--- a/engine/dub.sdl
+++ b/engine/dub.sdl
@@ -1,4 +1,4 @@
 name "engine"
 license "LGPL-3.0"
-targetType "dynamicLibrary"
+targetType "library"
 targetName "gameengine"
\ No newline at end of file
diff --git a/engine/source/core/engine.d b/engine/source/core/engine.d
index ff834d6..8c04ac3 100644
--- a/engine/source/core/engine.d
+++ b/engine/source/core/engine.d
@@ -1,44 +1,64 @@
 module gameengine.core.engine;
 
-import gameengine.renderer;
+import gameengine.graphics.drawable;
+import gameengine.renderer.renderer;
 import gameengine.node.node;
-import core.time;
+import std.datetime.stopwatch;
+
+import std.stdio;
+import std.format;
 
 class Engine {
-	this(IRenderer* renderer) {
+	this(Renderer renderer) {
 		this.renderer = renderer;
-		previousProcessTick = MonoTime.currTime();
-		previousPhysicsProcessTick = MonoTime.currTime();
+		previousProcessTick = 0.00001f;
+		previousPhysicsProcessTick = 0.00001f;
+
+		watch.start();
+	}
+
+	~this() {
+		watch.stop();
 	}
 
 	void runNodeProcesses() {
-		MonoTime currentTime = MonoTime.currTime();
+		// TODO: fix delta then adapt for runNodePhysicsProcesses
+		float current = watch.peek.total!"msecs" / 1_000;
+		float delta = (current - previousProcessTick);
 
-		Duration difference = currentTime - previousProcessTick;
-
-		float delta = difference.total!"hnsecs" / 10_000_000.0;
-
-		// Temp
-		debug { import std.stdio : writeln; import std.format; try { writeln(format("%f", delta)); } catch (Exception) {} }
 		foreach (Node* node ; nodeList) {
 			node.process(delta);
 		}
 
-		this.previousProcessTick = MonoTime.currTime();
+		this.previousProcessTick = watch.peek.total!"msecs" / 1_000;
 	}
 
 	void runNodePhysicsProcesses() {
 		// Schade!
-		this.previousPhysicsProcessTick = MonoTime.currTime();
+		float current = watch.peek.total!"msecs" / 1_000;
+		float delta = (current - previousProcessTick);
+
+		foreach (Node* node ; nodeList) {
+			node.physicsProcess(delta);
+		}
+
+		this.previousPhysicsProcessTick = watch.peek.total!"msecs" / 1_000;
 	}
 
-	void drawNodes() {}
+	void drawNodes() {
+		foreach (Node* node; nodeList) {
+			if (Drawable* drawNode = cast(Drawable*) node) {
+				drawNode.draw(&renderer);
+			}
+		}
+	}
 
 	string engineVersion() const { return "0.0.0"; }
 
-	private IRenderer* renderer;
-	private MonoTime previousProcessTick;
-	private MonoTime previousPhysicsProcessTick;
+	private Renderer renderer;
+	private StopWatch watch;
+	private float previousProcessTick;
+	private float previousPhysicsProcessTick;
 
 	private Node*[] nodeList;
 }
\ No newline at end of file
diff --git a/engine/source/graphics/drawable.d b/engine/source/graphics/drawable.d
index fdb60e3..6f4ff5b 100644
--- a/engine/source/graphics/drawable.d
+++ b/engine/source/graphics/drawable.d
@@ -1,6 +1,6 @@
 module gameengine.graphics.drawable;
-import gameengine.renderer;
+import gameengine.renderer.renderer;
 
 abstract class Drawable {
-	abstract void draw(IRenderer* renderer);
+	abstract void draw(Renderer* renderer);
 }
\ No newline at end of file
diff --git a/engine/source/renderer.d b/engine/source/renderer.d
deleted file mode 100644
index 3624e05..0000000
--- a/engine/source/renderer.d
+++ /dev/null
@@ -1,5 +0,0 @@
-module gameengine.renderer;
-
-interface IRenderer {
-	void setWindowTitle(string str);
-}
\ No newline at end of file
diff --git a/engine/source/renderer/renderer.d b/engine/source/renderer/renderer.d
new file mode 100644
index 0000000..d0efe06
--- /dev/null
+++ b/engine/source/renderer/renderer.d
@@ -0,0 +1,5 @@
+module gameengine.renderer.renderer;
+
+abstract class Renderer {
+	void setWindowTitle(string str);
+}
\ No newline at end of file
diff --git a/renderer/rsdl/dub.sdl b/renderer/rsdl/dub.sdl
index 2700496..ef193a0 100644
--- a/renderer/rsdl/dub.sdl
+++ b/renderer/rsdl/dub.sdl
@@ -1,6 +1,6 @@
 name "rsdl"
 dependency "gameengine:engine" version=">=0.0.0"
 dependency "bindbc-sdl" version="~>1.3.5"
-targetType "dynamicLibrary"
+targetType "library"
 targetName "gameengine_rsdl"
 sourcePaths "./" "../../engine/source"
diff --git a/renderer/rsdl/source/gameengine_rsdl/package.d b/renderer/rsdl/source/gameengine_rsdl/package.d
new file mode 100644
index 0000000..5dd1e9a
--- /dev/null
+++ b/renderer/rsdl/source/gameengine_rsdl/package.d
@@ -0,0 +1,7 @@
+module gameengine_rsdl;
+
+import gameengine.renderer.renderer;
+
+class RSDL : Renderer {
+	override void setWindowTitle(string title) {}
+}
\ No newline at end of file
diff --git a/renderer/rsdl/source/rsdl.d b/renderer/rsdl/source/rsdl.d
deleted file mode 100644
index 43d1634..0000000
--- a/renderer/rsdl/source/rsdl.d
+++ /dev/null
@@ -1,7 +0,0 @@
-module gameengine.renderer.sdl;
-
-import gameengine.renderer;
-
-class RSDL : IRenderer {
-	
-}
\ No newline at end of file
diff --git a/test/.gitignore b/test/.gitignore
new file mode 100644
index 0000000..8397f9a
--- /dev/null
+++ b/test/.gitignore
@@ -0,0 +1,16 @@
+.dub
+docs.json
+__dummy.html
+docs/
+/test
+test.so
+test.dylib
+test.dll
+test.a
+test.lib
+test-test-*
+*.exe
+*.pdb
+*.o
+*.obj
+*.lst
diff --git a/test/dub.sdl b/test/dub.sdl
new file mode 100644
index 0000000..e17d96b
--- /dev/null
+++ b/test/dub.sdl
@@ -0,0 +1,9 @@
+name "test"
+description "Test of the game engine"
+authors "Tulpenkiste"
+copyright "Copyright © 2023, Tulpenkiste"
+license "GPL-3.0"
+targetType "executable"
+dependency "gameengine:engine" version="*"
+dependency "gameengine:rsdl" version="*"
+sourcePaths "./" "../engine/source" "../../renderer/rsdl/source"
\ No newline at end of file
diff --git a/test/source/app.d b/test/source/app.d
new file mode 100644
index 0000000..c2713a8
--- /dev/null
+++ b/test/source/app.d
@@ -0,0 +1,17 @@
+import std.stdio;
+
+import gameengine.core.engine;
+import gameengine.renderer.renderer;
+import gameengine_rsdl;
+
+import core.thread;
+
+void main() {
+	Renderer renderer = new RSDL();
+	Engine engine = new Engine(renderer);
+
+	while (true) {
+		engine.runNodeProcesses();
+		Thread.sleep(1.msecs);
+	}
+}