diff --git a/turtle-lib/examples/cartesian_axes.rs b/turtle-lib/examples/cartesian_axes.rs
new file mode 100644
index 0000000..7648582
--- /dev/null
+++ b/turtle-lib/examples/cartesian_axes.rs
@@ -0,0 +1,114 @@
+//! Cartesian coordinate system example
+//!
+//! This example draws a cartesian coordinate system with X and Y axes,
+//! labeled axis endpoints, and 4 labeled points (one in each quadrant).
+
+use macroquad::prelude::*;
+use turtle_lib::*;
+
+#[turtle_main("Cartesian Axes")]
+fn draw(turtle: &mut TurtlePlan) {
+    const AXIS_LENGTH: f32 = 250.0;
+    const GRID_STEP: f32 = 50.0;
+    const FONT_SIZE: i32 = 16;
+    const SMALL_FONT: i32 = 24;
+
+    // Draw coordinate system center and axes
+    turtle
+        .reset()
+        .set_speed(1100)
+        .pen_up()
+        .go_to(vec2(0.0, 0.0))
+        .pen_down();
+
+    // Draw X axis (horizontal)
+    turtle.set_pen_color(macroquad::prelude::BLACK);
+    turtle.set_pen_width(2.0);
+    turtle.pen_up().go_to(vec2(-AXIS_LENGTH, 0.0)).pen_down();
+    turtle.forward(2.0 * AXIS_LENGTH);
+
+    // Draw Y axis (vertical)
+    turtle.pen_up().go_to(vec2(0.0, -AXIS_LENGTH)).pen_down();
+    turtle.set_heading(90.0);
+    turtle.forward(2.0 * AXIS_LENGTH);
+
+    // Draw axis tick marks (major and minor)
+    turtle.set_pen_width(1.0);
+    const MINOR_STEP: f32 = GRID_STEP / 10.0; // 1/10th markers
+
+    let mut pos = -AXIS_LENGTH;
+    while pos <= AXIS_LENGTH {
+        if (pos - 0.0).abs() > 1.0 {
+            // Skip origin
+            // Determine if this is a major or minor tick
+            let is_major = (pos / GRID_STEP).abs().fract() < 0.01;
+            let tick_length = if is_major { 10.0 } else { 5.0 };
+
+            // X axis tick
+            turtle
+                .pen_up()
+                .set_pen_width(tick_length / 5.0)
+                .go_to(vec2(pos, -tick_length / 2.0))
+                .pen_down()
+                .set_heading(90.0)
+                .forward(tick_length);
+
+            // Y axis tick
+            turtle
+                .pen_up()
+                .go_to(vec2(-tick_length / 2.0, pos))
+                .set_pen_width(tick_length / 5.0)
+                .pen_down()
+                .set_heading(0.0)
+                .forward(tick_length);
+        }
+        pos += MINOR_STEP;
+    }
+
+    // Label axes
+    turtle
+        .pen_up()
+        .go_to(vec2(AXIS_LENGTH + 20.0, 0.0))
+        .set_heading(0.0)
+        .write_text("X", FONT_SIZE);
+
+    turtle
+        .pen_up()
+        .go_to(vec2(0.0, AXIS_LENGTH + 20.0))
+        .set_heading(0.0)
+        .write_text("Y", FONT_SIZE);
+
+    // Draw and label 4 points (one per quadrant)
+    let points = vec![
+        (vec2(120.0, 100.0), "A(2|1)"),
+        (vec2(-120.0, 100.0), "B(-2|1)"),
+        (vec2(-120.0, -100.0), "C(-2|-1)"),
+        (vec2(120.0, -100.0), "D(2|-1)"),
+    ];
+
+    for (position, label) in points {
+        // Draw point as small circle
+        turtle
+            .pen_up()
+            .go_to(position)
+            .set_pen_color(macroquad::prelude::RED)
+            .set_pen_width(7.0)
+            .pen_down()
+            .forward(1.0); // Just a small mark
+
+        // Add label
+        let label_offset = vec2(label.len() as f32 * 2.5, 0.0);
+        turtle
+            .pen_up()
+            .go_to(position - label_offset)
+            .set_heading(0.0)
+            .write_text(label, SMALL_FONT);
+    }
+
+    // Label origin
+    turtle
+        .pen_up()
+        .go_to(vec2(-30.0, -20.0))
+        .set_heading(0.0)
+        .write_text("O", FONT_SIZE);
+}
diff --git a/turtle-lib/examples/cheese.rs b/turtle-lib/examples/cheese.rs
index 6d7fe40..eb4f11b 100644
--- a/turtle-lib/examples/cheese.rs
+++ b/turtle-lib/examples/cheese.rs
@@ -35,7 +35,7 @@ async fn main() {
 
     // Draw triangular hole in the middle
     println!("Drawing triangular hole...");
-    turtle.go_to(vec2(200.0, 120.0));
+    turtle.go_to(vec2(200.0, -120.0));
     turtle.pen_down(); // Start new contour for hole
 
     for _ in 0..3 {
@@ -48,7 +48,7 @@ async fn main() {
 
     // Draw circular hole (top-left) using circle_left
     println!("Drawing circular hole (top-left) with circle_left...");
-    turtle.go_to(vec2(100.0, 100.0));
+    turtle.go_to(vec2(100.0, -100.0));
     turtle.pen_down(); // Start new contour for hole
     turtle.circle_left(30.0, 360.0, 36); // radius=30, full circle, 36 steps
     println!("Closing circle contour with pen_up");
@@ -56,7 +56,7 @@ async fn main() {
 
     // Draw circular hole (bottom-right) using circle_right
     println!("Drawing circular hole (bottom-right) with circle_right...");
-    turtle.go_to(vec2(280.0, 280.0));
+    turtle.go_to(vec2(280.0, -280.0));
     turtle.pen_down(); // Start new contour for hole
     turtle.circle_right(40.0, 360.0, 36); // radius=40, full circle, 36 steps
     println!("Closing circle contour with pen_up");
diff --git a/turtle-lib/examples/cheese_macro.rs b/turtle-lib/examples/cheese_macro.rs
index 2bc8246..1022605 100644
--- a/turtle-lib/examples/cheese_macro.rs
+++ b/turtle-lib/examples/cheese_macro.rs
@@ -28,7 +28,7 @@ fn draw_cheese(turtle: &mut TurtlePlan) {
 
     // Draw triangular hole in the middle
     println!("Drawing triangular hole...");
-    turtle.go_to(vec2(200.0, 120.0));
+    turtle.go_to(vec2(200.0, -120.0));
     turtle.pen_down(); // Start new contour for hole
 
     for _ in 0..3 {
@@ -41,7 +41,7 @@ fn draw_cheese(turtle: &mut TurtlePlan) {
 
     // Draw circular hole (top-left) using circle_left
     println!("Drawing circular hole (top-left) with circle_left...");
-    turtle.go_to(vec2(100.0, 100.0));
+    turtle.go_to(vec2(100.0, -100.0));
     turtle.pen_down(); // Start new contour for hole
     turtle.circle_left(30.0, 360.0, 36); // radius=30, full circle, 36 steps
     println!("Closing circle contour with pen_up");
@@ -49,7 +49,7 @@ fn draw_cheese(turtle: &mut TurtlePlan) {
 
     // Draw circular hole (bottom-right) using circle_right
     println!("Drawing circular hole (bottom-right) with circle_right...");
-    turtle.go_to(vec2(280.0, 280.0));
+    turtle.go_to(vec2(280.0, -280.0));
     turtle.pen_down(); // Start new contour for hole
     turtle.circle_right(40.0, 360.0, 36); // radius=40, full circle, 36 steps
     println!("Closing circle contour with pen_up");
diff --git a/turtle-lib/examples/hangman_threaded.rs b/turtle-lib/examples/hangman_threaded.rs
index 98e473d..b854072 100644
--- a/turtle-lib/examples/hangman_threaded.rs
+++ b/turtle-lib/examples/hangman_threaded.rs
@@ -83,8 +83,6 @@ fn run_game_logic(
         smiley_tx.send(plan.build()).ok();
     }
 
-    draw_smiley(&smiley_tx, true);
-
     // Setup: Position hangman turtle and draw base (hill)
     {
         let mut plan = create_turtle_plan();
diff --git a/turtle-lib/examples/sierpinski_triangle.rs b/turtle-lib/examples/sierpinski_triangle.rs
index 2d8bf44..e451f6c 100644
--- a/turtle-lib/examples/sierpinski_triangle.rs
+++ b/turtle-lib/examples/sierpinski_triangle.rs
@@ -90,7 +90,7 @@ fn sierpinski_triangle_auto(turtle: &mut TurtlePlan, level: u8) {
     let size = TRIANGLE_SIZE;
 
     turtle.pen_up();
-    turtle.go_to((-screen_width() / 2.0 + 20.0, screen_height() / 2.0 - 20.0));
+    turtle.go_to((-screen_width() / 2.0 + 20.0, -screen_height() / 2.0 + 20.0));
     turtle.set_heading(0.0); // 0 = East (pointing right)
 
     // The drawing itself.