Here's a chess problem which plays very like a sliding-block puzzle, hence the rather unusual tag combo.
Ljubomir Ugren 2nd Prize, Mat, 1976; John Nunn, Solving in Style, no. 183
To explain that stipulation "sh#19": This problem is a serieshelpmate in 19. In a serieshelpmate, Black starts, and plays a series of moves, with no White moves in between. Then, at the end, White plays one move, which checkmates Black. Black is not allowed to move so that his king is in check. Black is not allowed to give check on any move except the last move of the series. In this problem, Black plays a series of 19 moves before White plays the final checkmating move.
You, the solver, stipulate all the moves -- that's the help bit. It's not like an orthodox problem where you must specify what White does against any defence from Black.