diff --git a/picoled b/picoled
index eab338e..1c9fc51 160000
--- a/picoled
+++ b/picoled
@@ -1 +1 @@
-Subproject commit eab338e380c9f7f30a3699097bf925214415120b
+Subproject commit 1c9fc51d01e3f5579b25f4b291b4fa01fdd83faf
diff --git a/pong/src/main.cpp b/pong/src/main.cpp
index 43ff088..a640c68 100644
--- a/pong/src/main.cpp
+++ b/pong/src/main.cpp
@@ -1,3 +1,4 @@
+#include <cmath>
 #include <cstdlib>
 
 #include <pico/stdio_usb.h>
@@ -5,9 +6,59 @@
 
 #include <picoled/SSD1306.h>
 
+namespace
+{
+
+struct rect
+{
+  float x, y, w, h;
+
+  void draw(picoled::oled& oled) const
+  {
+    for (int i = 0; i < w; i++)
+    {
+      for (int j = 0; j < h; j++)
+      {
+        oled(x + i, y + j) = true;
+      }
+    }
+  }
+
+  float left() const { return x; }
+  float right() const { return x + w; }
+  float top() const { return y; }
+  float bottom() const { return y + h; }
+
+  float middle_h() const { return x + w / 2.0f; }
+  float middle_v() const { return y + h / 2.0f; }
+
+  bool overlaps(const rect& other) const
+  {
+    const bool x_overlaps =
+      (left() >= other.left() && left() <= other.right()) ||
+      (right() >= other.left() && right() <= other.right());
+
+    const bool y_overlaps =
+      (top() >= other.top() && top() <= other.bottom()) ||
+      (bottom() >= other.top() && bottom() <= other.bottom());
+
+    return x_overlaps && y_overlaps;
+  }
+};
+
+constexpr uint8_t LEFT_BUTTON   = 2;
+constexpr uint8_t MIDDLE_BUTTON = 3;
+constexpr uint8_t RIGHT_BUTTON  = 4;
+
+constexpr float PADDLE_SPEED = 20;
+constexpr float INITIAL_BALL_SPEED = 32;
+
+}
+
 int main()
 {
   stdio_usb_init();
+  srand(time_us_64());
 
   i2c_init(i2c0, 3 * 1000 * 1000);
   gpio_set_function(0, GPIO_FUNC_I2C);
@@ -15,19 +66,97 @@ int main()
   gpio_pull_up(0);
   gpio_pull_up(1);
 
+  gpio_set_function(LEFT_BUTTON, GPIO_FUNC_SIO);
+  gpio_set_function(MIDDLE_BUTTON, GPIO_FUNC_SIO);
+  gpio_set_function(RIGHT_BUTTON, GPIO_FUNC_SIO);
+  gpio_set_dir(LEFT_BUTTON, GPIO_IN);
+  gpio_set_dir(MIDDLE_BUTTON, GPIO_IN);
+  gpio_set_dir(RIGHT_BUTTON, GPIO_IN);
+  gpio_pull_down(LEFT_BUTTON);
+  gpio_pull_down(MIDDLE_BUTTON);
+  gpio_pull_down(RIGHT_BUTTON);
+
   picoled::ssd1306 oled(i2c0, 0x3C);
   oled.update();
 
+  rect player = { 8.0f, oled.get_height() / 2.0f - 8.0f, 4.0f, 16.0f };
+  rect ai = { oled.get_width() - 8.0f - 4.0f, oled.get_height() / 2.0f - 8.0f, 4.0f, 16.0f };
+  rect ball = { 64.0f - 2.0f, 32.0f - 2.0f, 4.0f, 4.0f };
+  float ball_dir = (((rand() % 1000000) / 1000000.0f) - 0.5f) * 3.1415926f * 2.0f;
+  float ball_dx = cosf(ball_dir);
+  float ball_dy = sinf(ball_dir);
+  float ball_speed = INITIAL_BALL_SPEED;
+
+  int64_t us = time_us_32();
+
   while (true)
   {
-    for (int i = 0; i < 16; i++)
-    {
-      const int x = rand() % oled.get_width();
-      const int y = rand() % oled.get_height();
+    oled.clear();
 
-      oled(x, y).invert();
+    for (int i = 0; i < oled.get_width(); i++)
+    {
+      oled(i, 0) = true;
+      oled(i, oled.get_height() - 1) = true;
     }
 
+    for (int i = 0; i < oled.get_height(); i++)
+    {
+      oled(0, i) = true;
+      oled(oled.get_width() - 1, i) = true;
+    }
+
+    int64_t current = time_us_32();
+    float dt = std::abs(current - us) / 1000000.0f;
+    us = current;
+
+    if (gpio_get(LEFT_BUTTON)) { player.y -= PADDLE_SPEED * dt; }
+    if (gpio_get(MIDDLE_BUTTON)) { player.y += PADDLE_SPEED * dt; }
+
+    float diff = ball.middle_v() - ai.middle_v();
+    ai.y += 1.35f * diff * dt;
+
+    ball.x += ball_dx * dt * ball_speed;
+    ball.y += ball_dy * dt * ball_speed;
+
+    if (ball.overlaps(player))
+    {
+      ball_dx = -ball_dx;
+      ball.x = player.right();
+      ball_speed += 1.0f;
+    }
+    if (ball.overlaps(ai))
+    {
+      ball_dx = -ball_dx;
+      ball.x = ai.left() - ball.w;
+      ball_speed += 1.0f;
+    }
+
+    if (ball.left() < 0)
+    {
+      ball_dx = -ball_dx;
+      ball.x = 0;
+    }
+    if (ball.right() >= oled.get_width())
+    {
+      ball_dx = -ball_dx;
+      ball.x = oled.get_width() - ball.w;
+    }
+
+    if (ball.top() < 0)
+    {
+      ball_dy = -ball_dy;
+      ball.y = 0;
+    }
+    if (ball.bottom() >= oled.get_height())
+    {
+      ball_dy = -ball_dy;
+      ball.y = oled.get_height() - ball.h;
+    }
+
+    player.draw(oled);
+    ai.draw(oled);
+    ball.draw(oled);
+
     oled.update();
   }
 }