===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,56 @@
-/****
+/**** 
+* Classes
+****/ 
+// AntivirusAgent class: player-controlled agent
+var AntivirusAgent = Container.expand(function () {
+	var self = Container.call(this);
+	// Attach agent asset (placeholder: 'antivirusAgent')
+	var agentAsset = self.attachAsset('antivirusAgent', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	// Track last position for event triggers
+	self.lastX = 0;
+	self.lastY = 0;
+	// Update method stub
+	self.update = function () {
+		// To be implemented: movement, collision, etc.
+	};
+	return self;
+});
+// SystemFile class: files to protect from infection
+var SystemFile = Container.expand(function () {
+	var self = Container.call(this);
+	// Attach file asset (placeholder: 'systemFile')
+	var fileAsset = self.attachAsset('systemFile', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	// Infection state
+	self.infected = false;
+	return self;
+});
+// Virus class: viruses that move toward system files
+var Virus = Container.expand(function () {
+	var self = Container.call(this);
+	// Attach virus asset (placeholder: 'virus')
+	var virusAsset = self.attachAsset('virus', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	// Track last position for event triggers
+	self.lastX = 0;
+	self.lastY = 0;
+	// Update method stub
+	self.update = function () {
+		// To be implemented: movement, infection logic, etc.
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
 	backgroundColor: 0x000000
 });
\ No newline at end of file