Unless you are experienced with gamecode, or can remember what you changed and go back and change it back, it's probably not a good idea for just anyone to go digging around in the game code and changing things. If certain information is stored in more than one place, or effects more than one thing, then you could crash your game or render it unplayable. If you're willing to take that risk though it could be a fun learning experience. Of course it would probably be considered 'modding' so you wouldn't be able to play the game with altered files for challenges. I have discovered that even some small 'fixes' that simply turn an object on so you can use it from buydebug - like the fastfood van - can crash the game. I believe it was the space for the fastfood van. As soon as you clicked it the game crashed.