As the title suggests, this is a repost. The original link be viewed at https://www.graalians.com/forums/showthread.php?t=40417 if you would like to view it directly. Anyways, I have a decent amount of knowledge in this field so I would like to generally answer the original posters question (even if is quite old.). So, the question goes, "So why not do what Graal Era does and remove the ability for players to go into the files without being banned?". I think he is talking about the application files, which you can do through apps and you can't really get banned for that, as you can do that for years. He then mentions it could stop hackers which is completely false, they do not need access to there is generally not too much you can do other then view some basic gani file names and some image files. A couple commenters also touch upon this, saying all you can do is get access to read only files which is true, so it's basically useless. So I will tell you the real reason you can still "hack" on this game, it is due to memory editing. Every game has memory, and atleast some of it can be edited: such as editing the memory address of walking. This memory is on the Client Side, which is your device, while some memory, such as Gralats, is stored on the Server Side (which is self explanatory ). That is the reason no "Gralat Hacks" have existed, other then some game breaking exploits, because you cannot directly edit your Gralats. If you know a tiny bit of programming, you probably know what a string is, if not, is just text. Most animations are controlled by a "Gani" which in simple terms is just a string, so you can edit that string to perform other animations, which is why those were so popular back in the days. Anyways, if you have any questions about this (that is not directly asked how to hack the game, because I will ignore that) feel free to ask and I will try to respond .

TL;DR
Memory editing, thats why it cant be quite fully patched.