Move 4 Rooks into the 4 corner squares and the 5th piece in the middle to win.
 
A piece must be orthogonally adjacent to another piece in order to move. Pieces move like in Chess.
 
Variant 2: Four Rooks and a Bishop.
Variant 3: Four Knights and a Rook.
Variant 4: Four Bishops and a Rook. In this variant the Rook has to end up on its original square c2, NOT in the center.

 
 
For similar games see the Zillions games 'Entropy Cross' and 'Entropy Puzzle'.
 
More freeware as well as real puzzles and games at my homepage http://karl.kiwi.gen.nz.