Once you have installed additional level sets on your computer, you can access these level sets from the game as follows. From the Main Menu, click on ‘Options’. From the Options Menu, click on ‘Change Level Set’. This should bring up a list of all the installed level sets. Click on the desired level set, then click on ‘Return To Main Menu.’ When you click on ‘Play’, the Level Select Map will show the new level set. The program remembers the last level set you have selected, so each time you play Mad Scientist, it returns to the level set you were using the last time you played.