diff --git a/index.html b/index.html
index 521bbf9..f735746 100644
--- a/index.html
+++ b/index.html
@@ -71,6 +71,7 @@
     <script src="src/utils/Pathfinding.js"></script>
     <script src="src/utils/Compression.js"></script>
     <script src="src/utils/PerformanceMonitor.js"></script>
+    <script src="src/utils/IntegrationTests.js"></script>
 
     <!-- Data -->
     <script src="src/data/CraftingRecipes.js"></script>
diff --git a/src/utils/IntegrationTests.js b/src/utils/IntegrationTests.js
new file mode 100644
index 0000000..fae9349
--- /dev/null
+++ b/src/utils/IntegrationTests.js
@@ -0,0 +1,252 @@
+/**
+ * INTEGRATION TEST SUITE
+ * Automated tests to verify all systems work together
+ * Run with: IntegrationTests.runAll()
+ */
+
+class IntegrationTests {
+    constructor(scene) {
+        this.scene = scene;
+        this.results = [];
+        this.passCount = 0;
+        this.failCount = 0;
+    }
+
+    /**
+     * Run all integration tests
+     */
+    runAll() {
+        console.log('🧪 Starting Integration Tests...');
+        this.results = [];
+        this.passCount = 0;
+        this.failCount = 0;
+
+        // System existence tests
+        this.testSystemsExist();
+
+        // Cross-system integration tests
+        this.testInventorySystem();
+        this.testMountSystem();
+        this.testPerennialCrops();
+        this.testGemDropSystem();
+        this.testCraftingRecipes();
+        this.testPlaytimeTracker();
+        this.testSaveSystem();
+
+        // Performance tests
+        this.testPerformance();
+
+        // Output results
+        this.printResults();
+    }
+
+    /**
+     * Test helper
+     */
+    test(name, condition, errorMsg = '') {
+        const passed = condition;
+        this.results.push({ name, passed, errorMsg });
+
+        if (passed) {
+            this.passCount++;
+            console.log(`✅ ${name}`);
+        } else {
+            this.failCount++;
+            console.error(`❌ ${name}${errorMsg ? ': ' + errorMsg : ''}`);
+        }
+
+        return passed;
+    }
+
+    /**
+     * TEST SUITE: Systems Existence
+     */
+    testSystemsExist() {
+        console.log('\n🔍 Testing System Existence...');
+
+        this.test('TerrainSystem exists', !!this.scene.terrainSystem);
+        this.test('InventorySystem exists', !!this.scene.inventorySystem);
+        this.test('LootSystem exists', !!this.scene.lootSystem);
+        this.test('WeatherSystem exists', !!this.scene.weatherSystem);
+        this.test('Player exists', !!this.scene.player);
+
+        // Check Antigravity namespace
+        this.test('Antigravity namespace exists', !!window.Antigravity);
+        this.test('Antigravity.Systems exists', !!window.Antigravity.Systems);
+    }
+
+    /**
+     * TEST SUITE: Inventory System
+     */
+    testInventorySystem() {
+        console.log('\n🎒 Testing Inventory System...');
+
+        const inv = this.scene.inventorySystem;
+        if (!inv) {
+            this.test('Inventory System Integration', false, 'InventorySystem not found');
+            return;
+        }
+
+        // Test add/remove items
+        const initialCount = inv.getItemCount('wheat_seed') || 0;
+        inv.addItem('wheat_seed', 10);
+        const afterAdd = inv.getItemCount('wheat_seed');
+        this.test('Inventory add item', afterAdd === initialCount + 10);
+
+        inv.removeItem('wheat_seed', 5);
+        const afterRemove = inv.getItemCount('wheat_seed');
+        this.test('Inventory remove item', afterRemove === initialCount + 5);
+
+        // Cleanup
+        inv.removeItem('wheat_seed', 5);
+    }
+
+    /**
+     * TEST SUITE: Mount System
+     */
+    testMountSystem() {
+        console.log('\n🫏 Testing Mount System...');
+
+        // Check if MountSystem class exists
+        this.test('MountSystem class exists', typeof MountSystem !== 'undefined');
+
+        // Check mount data
+        if (typeof MountSystem !== 'undefined') {
+            const tempMount = new MountSystem(this.scene, this.scene.player);
+            this.test('Donkey mount data exists', !!tempMount.mountData['donkey']);
+            this.test('Horse mount data exists', !!tempMount.mountData['horse']);
+        }
+    }
+
+    /**
+     * TEST SUITE: Perennial Crops
+     */
+    testPerennialCrops() {
+        console.log('\n🍎 Testing Perennial Crops System...');
+
+        this.test('PerennialCropSystem class exists', typeof PerennialCropSystem !== 'undefined');
+
+        if (typeof PerennialCropSystem !== 'undefined') {
+            const tempSystem = new PerennialCropSystem(this.scene);
+            this.test('Apple tree data exists', !!tempSystem.perennialData['apple_tree']);
+        }
+    }
+
+    /**
+     * TEST SUITE: Gem Drop System
+     */
+    testGemDropSystem() {
+        console.log('\n💎 Testing Gem Drop System...');
+
+        this.test('GemDropSystem class exists', typeof GemDropSystem !== 'undefined');
+
+        if (typeof GemDropSystem !== 'undefined') {
+            const tempSystem = new GemDropSystem(this.scene);
+            this.test('Diamond gem data exists', !!tempSystem.gems['diamond']);
+            this.test('Emerald gem data exists', !!tempSystem.gems['emerald']);
+            this.test('Ruby gem data exists', !!tempSystem.gems['ruby']);
+            this.test('Sapphire gem data exists', !!tempSystem.gems['sapphire']);
+        }
+    }
+
+    /**
+     * TEST SUITE: Crafting Recipes
+     */
+    testCraftingRecipes() {
+        console.log('\n🔨 Testing Crafting Recipes...');
+
+        this.test('CRAFTING_RECIPES exists', typeof CRAFTING_RECIPES !== 'undefined');
+
+        if (typeof CRAFTING_RECIPES !== 'undefined') {
+            this.test('Bone pickaxe recipe exists', !!CRAFTING_RECIPES['bone_pickaxe']);
+            this.test('Bone axe recipe exists', !!CRAFTING_RECIPES['bone_axe']);
+            this.test('Bone hoe recipe exists', !!CRAFTING_RECIPES['bone_hoe']);
+            this.test('Bone sword recipe exists', !!CRAFTING_RECIPES['bone_sword']);
+        }
+    }
+
+    /**
+     * TEST SUITE: Playtime Tracker
+     */
+    testPlaytimeTracker() {
+        console.log('\n⏱️ Testing Playtime Tracker...');
+
+        this.test('PlaytimeTrackerSystem class exists', typeof PlaytimeTrackerSystem !== 'undefined');
+
+        if (typeof PlaytimeTrackerSystem !== 'undefined') {
+            const tempTracker = new PlaytimeTrackerSystem(this.scene);
+            this.test('Tracker has stats object', !!tempTracker.stats);
+            this.test('Tracker has playtimeSeconds', typeof tempTracker.stats.playtimeSeconds === 'number');
+        }
+    }
+
+    /**
+     * TEST SUITE: Save System
+     */
+    testSaveSystem() {
+        console.log('\n💾 Testing Save System...');
+
+        this.test('SaveSystem class exists', typeof SaveSystem !== 'undefined');
+        this.test('localStorage available', typeof localStorage !== 'undefined');
+    }
+
+    /**
+     * TEST SUITE: Performance
+     */
+    testPerformance() {
+        console.log('\n📊 Testing Performance...');
+
+        // Check if game is running at acceptable FPS
+        if (this.scene.game && this.scene.game.loop) {
+            const fps = this.scene.game.loop.actualFps;
+            this.test('FPS above 30', fps > 30, `Current FPS: ${fps.toFixed(1)}`);
+            this.test('FPS above 50 (good)', fps > 50, `Current FPS: ${fps.toFixed(1)}`);
+        }
+
+        // Check sprite count (should not be too high)
+        if (this.scene.children) {
+            const spriteCount = this.scene.children.list.length;
+            this.test('Sprite count reasonable (<10000)', spriteCount < 10000, `Count: ${spriteCount}`);
+        }
+    }
+
+    /**
+     * Print test results summary
+     */
+    printResults() {
+        console.log('\n' + '='.repeat(50));
+        console.log('🧪 INTEGRATION TEST RESULTS');
+        console.log('='.repeat(50));
+        console.log(`✅ PASSED: ${this.passCount}`);
+        console.log(`❌ FAILED: ${this.failCount}`);
+        console.log(`📊 TOTAL:  ${this.results.length}`);
+        console.log(`📈 SUCCESS RATE: ${((this.passCount / this.results.length) * 100).toFixed(1)}%`);
+        console.log('='.repeat(50));
+
+        if (this.failCount === 0) {
+            console.log('🎉 All tests passed! Systems are integrated correctly!');
+        } else {
+            console.log('⚠️  Some tests failed. Check errors above.');
+        }
+
+        return {
+            passed: this.passCount,
+            failed: this.failCount,
+            total: this.results.length,
+            successRate: (this.passCount / this.results.length) * 100,
+            results: this.results
+        };
+    }
+}
+
+// Make available globally
+window.IntegrationTests = IntegrationTests;
+
+// Convenience function
+window.runTests = function () {
+    const scene = game.scene.scenes[0]; // Get GameScene
+    const tests = new IntegrationTests(scene);
+    return tests.runAll();
+};
+
+console.log('🧪 Integration Tests loaded. Run with: runTests()');