diff --git a/Cargo.toml b/Cargo.toml
index 2b84644..30a5c04 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,6 +2,7 @@
 name = "worlds-sim-rust"
 version = "0.1.0"
 edition = "2021"
+resolver = "2"
 
 [features]
 debug = ["save/debug"]
diff --git a/save/src/world_manager.rs b/save/src/world_manager.rs
index 9a84604..5982af5 100644
--- a/save/src/world_manager.rs
+++ b/save/src/world_manager.rs
@@ -18,6 +18,8 @@ pub struct WorldManager {
     rainfall_visible: bool,
     #[cfg(feature = "render")]
     temperature_visible: bool,
+    #[cfg(feature = "render")]
+    terrain_as_contours: bool,
 }
 
 impl WorldManager {
@@ -28,6 +30,7 @@ impl WorldManager {
             world: None,
             rainfall_visible: false,
             temperature_visible: false,
+            terrain_as_contours: false,
         }
     }
 
@@ -51,6 +54,16 @@ impl WorldManager {
         self.temperature_visible = !self.temperature_visible;
     }
 
+    #[cfg(feature = "render")]
+    pub fn toggle_contours(&mut self) {
+        if self.terrain_as_contours {
+            debug!("Turning terrain contours off");
+        } else {
+            debug!("Turning terrain contours on");
+        }
+        self.terrain_as_contours = !self.terrain_as_contours;
+    }
+
     pub fn get_world(&self) -> Option<&World> {
         self.world.as_ref()
     }
@@ -65,7 +78,11 @@ impl WorldManager {
 
     #[cfg(feature = "render")]
     fn generate_color(&self, cell: &TerrainCell) -> Color {
-        let mut final_color = Self::altitude_color(cell.altitude);
+        let mut final_color = if self.terrain_as_contours {
+            Self::altitude_contour_color(cell.altitude)
+        } else {
+            Self::altitude_color(cell.altitude)
+        };
 
         if self.rainfall_visible {
             let rainfall_color = Self::rainfall_color(cell.rainfall);
@@ -106,7 +123,6 @@ impl WorldManager {
         final_color
     }
 
-    /*
     #[cfg(feature = "render")]
     fn altitude_color(altitude: f32) -> Color {
         if altitude < 0.0 {
@@ -117,7 +133,6 @@ impl WorldManager {
             Color::rgb(0.58 * mult, 0.29 * mult, 0.0)
         }
     }
-    */
 
     #[cfg(feature = "render")]
     fn altitude_contour_color(altitude: f32) -> Color {
diff --git a/src/main.rs b/src/main.rs
index aa7a882..6113fdf 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -85,6 +85,10 @@ struct RainfallButton;
 #[derive(Component, Default)]
 struct TemperatureButton;
 
+#[cfg(feature = "render")]
+#[derive(Component, Default)]
+struct ContoursButton;
+
 const NORMAL_BUTTON: Color = Color::rgb(0.15, 0.15, 0.15);
 const HOVERED_BUTTON: Color = Color::rgb(0.25, 0.25, 0.25);
 const PRESSED_BUTTON: Color = Color::rgb(0.35, 0.60, 0.35);
@@ -154,6 +158,39 @@ fn handle_temperature_button(
     }
 }
 
+#[cfg(feature = "render")]
+fn handle_contours_button(
+    mut interaction_query: Query<
+        '_,
+        '_,
+        (&Interaction, &mut UiColor),
+        (Changed<Interaction>, With<ContoursButton>),
+    >,
+    mut windows: ResMut<'_, Windows>,
+    mut images: ResMut<'_, Assets<Image>>,
+    mut world_manager: ResMut<'_, WorldManager>,
+) {
+    for (interaction, mut color) in &mut interaction_query {
+        match *interaction {
+            Interaction::Clicked => {
+                windows.primary_mut().set_cursor_icon(CursorIcon::Default);
+                *color = PRESSED_BUTTON.into();
+                debug!("Toggling contours");
+                world_manager.toggle_contours();
+                refresh_world_texture(&mut images, &world_manager)
+            }
+            Interaction::Hovered => {
+                windows.primary_mut().set_cursor_icon(CursorIcon::Hand);
+                *color = HOVERED_BUTTON.into();
+            }
+            Interaction::None => {
+                windows.primary_mut().set_cursor_icon(CursorIcon::Default);
+                *color = NORMAL_BUTTON.into();
+            }
+        }
+    }
+}
+
 #[cfg(feature = "render")]
 fn generate_graphics(
     mut commands: Commands<'_, '_>,
@@ -256,6 +293,31 @@ fn generate_graphics(
                                 ..default()
                             });
                         });
+                    _ = button_box
+                        .spawn_bundle(ButtonBundle {
+                            button: Button,
+                            style: Style {
+                                align_items: AlignItems::Center,
+                                justify_content: JustifyContent::Center,
+                                ..default()
+                            },
+                            color: NORMAL_BUTTON.into(),
+                            ..default()
+                        })
+                        .insert(ContoursButton::default())
+                        .with_children(|button| {
+                            _ = button.spawn_bundle(TextBundle {
+                                text: bevy::text::Text::from_section(
+                                    "Toggle contours",
+                                    bevy::text::TextStyle {
+                                        font: asset_server.load("JuliaMono.ttf"),
+                                        font_size: 20.0,
+                                        color: Color::WHITE,
+                                    },
+                                ),
+                                ..default()
+                            });
+                        });
                 });
         });
 }
@@ -272,15 +334,16 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             // Use nearest-neighbor rendering for cripsier pixels
             .insert_resource(ImageSettings::default_nearest())
             .insert_resource(WindowDescriptor {
-                width: world.width as f32,
-                height: world.height as f32,
+                width: (2 * world.width) as f32,
+                height: (2 * world.height) as f32,
                 title: String::from("World-RS"),
                 resizable: true,
                 ..default()
             })
             .add_startup_system(generate_graphics)
             .add_system(handle_rainfall_button)
-            .add_system(handle_temperature_button);
+            .add_system(handle_temperature_button)
+            .add_system(handle_contours_button);
     }
     #[cfg(not(feature = "render"))]
     {