diff --git a/examples/guess-the-number/game.test.js b/examples/guess-the-number/game.test.js
new file mode 100644
index 0000000..71dcc6b
--- /dev/null
+++ b/examples/guess-the-number/game.test.js
@@ -0,0 +1,18 @@
+import { it, expect, describe, vi } from 'vitest';
+import { Game } from './game';
+
+describe('Game', () => {
+  it('should return an instance of a game', () => {
+    // This is mostly a dummy test.
+    const game = new Game(1, 10);
+    expect(game).toBeInstanceOf(Game);
+  });
+
+  it('should have a secret number', () => {
+    // Thisn't really a useful test.
+    // Do I *really* care about the type of the secret number?
+    // Do I *really* care about the name of a "private" property?
+    const game = new Game(1, 10);
+    expect(game.secretNumber).toBeTypeOf('number');
+  });
+});