While playing, press Shift to open the game menu. Choose the 3rd option and then highlight the BGM option. Now, hold C and wait for the text screen to appear completely, once it appears and while still holding C, press Up, Up, Down, Down, Right, Left, Right, Left and X. If done right, the debug menu will appear.
Start Disk 1 (Demo Disk) and hold the "B" key. It should load directly into the hidden art scenes. Once you've seen that set of screens, wait 5 minutes and press Space to see a second set of screens.
Hold G + O and load the following disks until the games start: