ok i dunno how that could be illegal man!! yes they have a copyright on the game but that is why we are not distributing a version of it or anything like that. and to tell the truth about that, as long as at least 10% of the idea/thing is changed it legaly isn't theirs anymore. by changing the way that the tileset system works (seeing that the tileset being a giant part of the program) would most likely be counted as a 10% since not only do you have a different way of access the tiles, but you have a now new thing that would easily replace all tilesets all together. thus making it legal, all because they changed enough of it, now if it was less of a change, yes it can be illegal assuming that they had said not to change the original code