It has been a long time since the last update. However I received an e-mail from nin10doadict about a week ago and it included some custom puzzles. They are very hard but if you like you can grab them here: RotBCustPuzzles. The file must be placed in the puzzles directory. Linux uses may also place the file in ~/.gamesaves/blockattack/puzzles/. To get an idea of the difficulty of the puzzles you might want to view his YouTube video here.