diff --git a/engine/src/engine/engine.rs b/engine/src/engine/engine.rs
index cf413b7..52a3465 100644
--- a/engine/src/engine/engine.rs
+++ b/engine/src/engine/engine.rs
@@ -25,10 +25,8 @@ impl TScene for GuiHandlerRenderer {
         indices: &TargetMode<usize>,
         world: &mut World,
     ) -> Result<()> {
-        world
-            .resources
-            .get_mut::<GuiHandler>()
-            .process(buffer_recorder, indices)
+        let gui_handler: &mut GuiHandler = world.resources.get_mut()?;
+        gui_handler.process(buffer_recorder, indices)
     }
 
     fn resize(
@@ -38,11 +36,8 @@ impl TScene for GuiHandlerRenderer {
         images: &TargetMode<Vec<Arc<Image>>>,
         world: &mut World,
     ) -> Result<()> {
-        world.resources.get_mut::<GuiHandler>().resize(
-            window_width as u32,
-            window_height as u32,
-            images,
-        )
+        let gui_handler: &mut GuiHandler = world.resources.get_mut()?;
+        gui_handler.resize(window_width as u32, window_height as u32, images)
     }
 }
 
diff --git a/engine/src/scene/content/components/audio.rs b/engine/src/scene/content/components/audio.rs
index b21983c..00514a9 100644
--- a/engine/src/scene/content/components/audio.rs
+++ b/engine/src/scene/content/components/audio.rs
@@ -182,7 +182,7 @@ impl EntityComponent for Audio {
             sound.stop_looping().unwrap();
         }
 
-        self.clear(world.resources.get_mut::<Context>())
+        self.clear(world.resources.get_mut()?)
     }
 }
 
diff --git a/engine/src/scene/content/components/location.rs b/engine/src/scene/content/components/location.rs
index abf7db5..40c1a97 100644
--- a/engine/src/scene/content/components/location.rs
+++ b/engine/src/scene/content/components/location.rs
@@ -62,14 +62,19 @@ impl Location {
         };
 
         entity.insert_component(location);
-        Self::setup(entity.multi_mut())?;
+        Self::setup(entity)?;
 
         Ok(entity.get_component_mut::<Self>()?)
     }
 
     pub fn setup(entity: &mut EntityObject) -> Result<()> {
-        let (location, draw, audio): (&mut Location, &mut Draw, &mut Audio) =
-            entity.get_components_mut()?;
+        let (location, draw, audio): (
+            Option<&mut Location>,
+            Option<&mut Draw>,
+            Option<&mut Audio>,
+        ) = entity.get_components_mut()?;
+
+        let location = location.unwrap();
 
         if let Some(draw) = draw {
             location.set_draw_callback(draw);
diff --git a/engine/src/scene/general/free_camera_control.rs b/engine/src/scene/general/free_camera_control.rs
index 084d12c..b63ab3e 100644
--- a/engine/src/scene/general/free_camera_control.rs
+++ b/engine/src/scene/general/free_camera_control.rs
@@ -24,6 +24,7 @@ impl<'a> From<&'a FreeCameraControl> for HoldInfo {
     }
 }
 
+#[derive(Resource)]
 pub struct FreeCameraControl {
     roll: Deg<f32>,
     pitch: Deg<f32>,
diff --git a/examples/free_space/src/game.rs b/examples/free_space/src/game.rs
index 2c43190..6c9490f 100644
--- a/examples/free_space/src/game.rs
+++ b/examples/free_space/src/game.rs
@@ -4,7 +4,7 @@ use anyhow::Result;
 
 use ecs::*;
 use engine::prelude::{
-    cgmath::{Vector3, Vector4, vec3, vec4},
+    cgmath::{Vector3, Vector4, vec3},
     *,
 };
 
@@ -341,13 +341,11 @@ impl Game {
         _entity: Entity,
         control: &mut FreeSpaceControl,
     ) -> Result<()> {
-        const DEFAULT_CENTER: Vector4<f32> = vec4(0.0, 0.0, 0.0, 1.0);
-
         let scene = world.resources.get_mut::<Scene>();
         let view = scene.view_mut();
 
         view.camera_mut()
-            .set_center((control.translation() * DEFAULT_CENTER).truncate());
+            .set_center((control.translation() * Vector4::unit_w()).truncate());
         view.camera_mut()
             .set_eye_dir(control.rotation() * Vector3::unit_y());
         view.camera_mut()
diff --git a/examples/simple_window/src/main.rs b/examples/simple_window/src/main.rs
index 24380c3..3f5d882 100644
--- a/examples/simple_window/src/main.rs
+++ b/examples/simple_window/src/main.rs
@@ -11,14 +11,15 @@ fn main() -> Result<()> {
     world_builder.add_system(GameState::update);
     world_builder.resources.insert(GameState::default());
 
-    let view = world_builder.resources.get_mut::<Scene>().view_mut();
+    let scene: &mut Scene = world_builder.resources.get_mut()?;
+    let view = scene.view_mut();
     let camera_control = FreeCameraControl::new(view)?;
     world_builder.resources.insert(camera_control);
 
     world_builder.build().run()
 }
 
-#[derive(Default)]
+#[derive(Default, Resource)]
 enum GameState {
     #[default]
     Startup,
@@ -60,17 +61,16 @@ impl Game {
     fn event(&mut self, world: &mut World, event: EngineEvent<'_>) -> Result<()> {
         match event {
             EngineEvent::MouseButtonDown(MouseButton::Left) => {
-                let camera_control = world.resources.get_mut::<FreeCameraControl>();
+                let camera_control: &mut FreeCameraControl = world.resources.get_mut()?;
                 camera_control.mouse_down();
             }
             EngineEvent::MouseButtonUp(MouseButton::Left) => {
-                let camera_control = world.resources.get_mut::<FreeCameraControl>();
+                let camera_control: &mut FreeCameraControl = world.resources.get_mut()?;
                 camera_control.mouse_release();
             }
             EngineEvent::MouseMotion(x, y) => {
-                let mut resources = world.resources.multi_mut();
-                let scene = resources.get::<Scene>();
-                let camera_control = resources.get::<FreeCameraControl>();
+                let (scene, camera_control): (&mut Scene, &mut FreeCameraControl) =
+                    world.resources.get_mut()?;
 
                 camera_control.mouse_move(x, y, scene.view_mut())?;
             }
diff --git a/skybox/src/lib.rs b/skybox/src/lib.rs
index dea9671..9b6daff 100644
--- a/skybox/src/lib.rs
+++ b/skybox/src/lib.rs
@@ -31,6 +31,7 @@ impl<T: ExactSizeIterator<Item = PathBuf>> From<T> for SkyBoxImages {
     }
 }
 
+#[derive(Resource)]
 pub struct SkyBox {
     enabled: bool,