diff --git a/src/main.zig b/src/main.zig
index c7b061a..9b4d978 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -2,12 +2,16 @@ const std = @import("std");
 const pong = @import("pong");
 const rl = @import("raylib");
 
+const State = enum { PAUSED, PLAYING };
+
 const player = struct {
     rect: *pong.Rectangle,
+    score: u8,
 
     fn init(rect: *pong.Rectangle) player {
         return player{
             .rect = rect,
+            .score = 0,
         };
     }
 
@@ -28,14 +32,82 @@ const player = struct {
             self.rect.y -= speed;
         }
     }
+
+    fn aiUpdate(self: *player, myball: ball) void {
+        const centerY = self.rect.y + self.rect.height / 2.0;
+        const moveSpeed = 5;
+
+        if (myball.rect.y > centerY) {
+            self.rect.y += moveSpeed;
+        }
+
+        if (myball.rect.y < centerY) {
+            self.rect.y -= moveSpeed;
+        }
+    }
 };
 
+const ball = struct {
+    rect: *pong.Rectangle,
+    vx: f32,
+    vy: f32,
+
+    fn init(rect: *pong.Rectangle, speed: f32, angle: f32) ball {
+        return ball{
+            .rect = rect,
+            .vx = speed * @cos(angle),
+            .vy = speed * @sin(angle),
+        };
+    }
+
+    fn update(self: *ball) void {
+        self.rect.x += self.vx;
+        self.rect.y += self.vy;
+    }
+
+    fn hitCanvas(self: *ball, screenWidth: f32, screenHeight: f32) void {
+        if (self.rect.y < 0 or self.rect.y > screenHeight) {
+            self.vx *= 1;
+            self.vy *= -1;
+        }
+
+        if (self.rect.x < 0 or self.rect.x > screenWidth) {
+            self.vx *= -1;
+            self.vy *= 1;
+        }
+    }
+
+    fn hitPaddle(self: *ball, rect: pong.Rectangle) void {
+        if (collision(self.rect.*, rect)) {
+            self.vx *= -1;
+            self.vy *= 1;
+        }
+    }
+
+    fn reset(self: ball, screenWidth: f32, screenHeight: f32) void {
+        self.rect.x = screenWidth / 2;
+        self.rect.y = screenHeight / 2;
+    }
+};
+
+fn collision(r1: pong.Rectangle, r2: pong.Rectangle) bool {
+    if ((r1.x <= r2.x + r2.width / 2.0 and r1.x + r1.width / 2.0 >= r2.x) and (r1.y <= r2.y + r2.height and r1.y + r1.height >= r2.y)) {
+        return true;
+    }
+
+    return false;
+}
+fn drawRectangle(rect: pong.Rectangle, colour: rl.Color) void {
+    rl.drawRectangle(@intFromFloat(rect.x), @intFromFloat(rect.y), @intFromFloat(rect.width), @intFromFloat(rect.height), colour);
+}
+
 pub fn main() anyerror!void {
     // Initialization
     //--------------------------------------------------------------------------------------
     const screenWidth = 800;
     const screenHeight = 450;
-    const speed = 4.0;
+    const speed = 6.0;
+    const pi = std.math.pi;
 
     // player rect
     var rect = pong.Rectangle.init(20, screenHeight / 2 - 40, 40, 80);
@@ -45,6 +117,10 @@ pub fn main() anyerror!void {
     var aiRect = pong.Rectangle.init(screenWidth - 20 * 3, screenHeight / 2 - 40, 40, 80);
     var ai = player.init(&aiRect);
 
+    // ball
+    var ballRect = pong.Rectangle.init(screenWidth / 2 - 5, screenHeight / 2 - 5, 10, 10);
+    var myBall = ball.init(&ballRect, speed, (pi / 4.0) * 3);
+
     rl.initWindow(screenWidth, screenHeight, "PONG");
     defer rl.closeWindow(); // Close window and OpenGL context
 
@@ -55,15 +131,38 @@ pub fn main() anyerror!void {
     while (!rl.windowShouldClose()) { // Detect window close button or ESC key
         // Update
         myPlayer.update(screenHeight, speed);
-        ai.update(screenHeight, speed);
+        if (myBall.rect.x > (screenWidth * 0.6) and myBall.vx > 0) {
+            ai.aiUpdate(myBall);
+        }
+
+        myBall.update();
+        myBall.hitCanvas(screenWidth, screenHeight);
+        myBall.hitPaddle(myPlayer.rect.*);
+        myBall.hitPaddle(ai.rect.*);
+
+        if (myBall.rect.x < 0) {
+            ai.score += 1;
+            myBall.reset(screenWidth, screenHeight);
+        }
+
+        if (myBall.rect.x > screenWidth) {
+            myPlayer.score += 1;
+            myBall.reset(screenWidth, screenHeight);
+        }
 
         // Draw
         rl.beginDrawing();
         defer rl.endDrawing();
 
-        rl.drawRectangle(@intFromFloat(myPlayer.rect.x), @intFromFloat(myPlayer.rect.y), @intFromFloat(myPlayer.rect.width), @intFromFloat(myPlayer.rect.height), .white);
-        rl.drawRectangle(@intFromFloat(ai.rect.x), @intFromFloat(ai.rect.y), @intFromFloat(ai.rect.width), @intFromFloat(ai.rect.height), .white);
         rl.drawText(rl.textFormat("y: %f", .{myPlayer.rect.y}), 10, 0, 20, .white);
+        rl.drawText(rl.textFormat("%d", .{myPlayer.score}), screenWidth / 2 - 80, 20, 40, .white);
+        rl.drawText(rl.textFormat("%d", .{ai.score}), screenWidth / 2 + 65, 20, 40, .white);
+
+        rl.drawLine(screenWidth / 2, 0, screenWidth / 2, screenHeight, .white);
+
+        drawRectangle(myPlayer.rect.*, .white);
+        drawRectangle(ai.rect.*, .white);
+        drawRectangle(myBall.rect.*, .white);
 
         rl.clearBackground(.black);
     }