Bonus Animation and Video:
Concealed within the Back End (the final room full of computers) is a special hidden thing revolving around the Spacemonkeyz dub of M1 A1, otherwise known as Li'l Dub Chiefin'. It's entirely possible for people to find this egg with the greatest of ease the first time they watch the DVD, only to discover that on subsequent viewings, they can't access it any more. And here's why.
Once the intro animation has played, and you're in the lobby with the jukebox, you must visit each room in order, from left to right as they appear in the menu bar (so that's Noodle's room, Murdoc's Room, 2D's Room, Russel's Room, the Toilets, the Cinema and the Back End). You must let each room load up completely, and once you're inside, you can select the next in the sequence. (Generally, people viewing the DVD for the first time will do this anyway, hence the confusion that comes later.)
You'll know if you've performed this correctly when you get to the seventh and final room, the Back End, because over the clicking and whirring of the PCs you'll be able to hear Li'l Dub Chiefin' being piped in from somewhere. In fact, it's coming from the air vent at the top left of the screen - so highlight it and press your Enter button. (If you visit the rooms out of order, you'll find it's impossible to highlight.)
Now all you have to do is sit back and watch a spiffy little animated sequence which leads into the full music video for Li'l Dub Chiefin', and a big credits sequence which finally reveals who really provides the voices for the characters when they're not singing…and it's not who you might expect.
Visit any of the first six rooms (Noodle's room, Murdoc's room, 2D's room, Russel's room, the Toilets or the Cinema) and just leave the controls alone for a few minutes. You'll have to wait quite some time, but eventually, some very strange things will start to happen (i.e. some hidden animations will begin to play)…and some of them seem to have something to do with the mysterious streaker whose face appears on the police photofit on the Gorillaz website.