Adds simple UI

test.py

@@ -20,12 +20,24 @@ def test_systems_tick():
         )
     )
 
-    entity = create_pet(world, "karabas")
+    create_pet(world, "karabas")
 
     for _ in range(81 + 35):
         world.tick()
         print(world.registry)
 
 
+def test_ui():
+    import pyglet
+
+    window = pyglet.window.Window()
+
+    @window.event
+    def on_draw():
+        window.clear()
+
+    pyglet.app.run()
+
+
 if __name__ == "__main__":
-    test_systems_tick()
+    test_ui()