As we're making frequent changes, sometimes, your browser cache gets clogged up with old assets - generally, you can get everything working again by pressing the 'Ctrl'+'F5' keys on your computer simultaneously.

It's also worth noting that it makes sense to make sure you're using an up-to-date web-browser and Flash Plug-in:

• The 'Help' menu in most web-browsers has a 'check for updates' option.
• The Flash plug-in is the bit of software that makes the games work. You can download it from http://www.adobe.com/shockwave/download.

A final note: the site is built for broadband internet connections. Unfortunately, dial-up connections tend to be very slow - everything should still work, but it will be a LOT slower.