You do not have the ability to tamper with your console if it is found that you did you will lose the full console you are also not allowed to tamper with the games or remix the console and games that would be copy right. (You cannot copyright scratch projects, scratch TOS confirms that the projects you make are owned by them, legally. You can even see that at the bottom it has a backwards copyright sign. :D) You do not have to buy anything! You can add your own accessories in the code! To get more then 15 games you have to add them yourself.
@SnapSlideDev for the original project. This is a free version which is limited.