You can move a piece as many places as there are pieces on this line (line = row, column or diagonal).
If you land on a piece, it will be captured.

Square-Deletion Rule:
If the target position contains a ball which is part of a 4-balls-in-a-square arrangement, then all 4 balls will be deleted. (Example: balls on a1, a3, c1, c3).
Note that the ball being moved cannot be part of such a arrangement if the 4-balls-in-a-square arrangement is to be deleted.

If the target ball is part of several such square arrangements, all those 4-ball arrangements will be deleted.

The colour of the balls has no relevance in this game.

Beginners: You win when only one piece is left.
Advanced: Solve the puzzle using the smallest number of moves, which is displayed at the right border.

Solutions to the fixed variants are attached (select Help/ShowSolution).

 
This is a puzzle in the tradition of the 2-player games Lines Of Action and Zen, where the length of a move is controlled by the number of pieces on that line. Related Zillions games: Powerlines, Squaredance.
The square-deletion rule make Powerball more complex than the game Powerlines (and hence more difficult to solve), and it also speeds up the game considerably, especially for setups with a large number of tokens.