I may have corrected the bug

controllers/prototype/index.js

@@ -169,3 +169,7 @@ module.exports.userstudy = function(req, res) {
     });
 
 };
+
+module.exports.next = function(req, res) {
+    res.redirect('/prototype/game')
+};

controllers/prototype/urls.js

@@ -9,5 +9,6 @@ module.exports = {
     '/prototype/coin-creator/:scene': 'clicker',
     '/prototype/coin-viewer/:scene': 'viewer',
     '/prototype/coin-checker/:scene': 'checker',
-    '/user-study': 'userstudy'
+    '/user-study': 'userstudy',
+    '/prototype/next': 'next'
 };

controllers/thankyou/index.js

@@ -1,4 +1,8 @@
 module.exports.index = function(req, res) {
+
+    req.session = null;
+    res.locals.session = null;
+
     res.setHeader('Content-Type', 'text/html');
 
     res.render('index.jade', res.locals, function(err, result) {

js/l3d/apps/prototype/interactive/main.js

@@ -32,13 +32,20 @@ Coin.onCoinGot = function(coin) {
         setTimeout(function() {
             $('#next').show();
             $('#next').click(function() {
-                window.location = '/prototype/game';
-                $('#next').unbind('click');
+                window.location = '/prototype/next';
             });
         }, 60*1000);
     }
 };
 
+Coin.onLastCoin = function() {
+    $('#next').show();
+    $('#next').click(function() {
+        window.location = '/prototype/next';
+    });
+
+}
+
 function main() {
 
     // Main container that holds everything