Burbuja

Solitaire game for Piecepack in which a 5x5 square must expand into a hollow 7x7 square in 24 moves or less. The level of difficulty is adjustable by allowing second chances at certain moves. The game will be won if the full square can be blown up as if it was a bubble (Spanish: ​burbuja) in no more than 24 moves. —description from the publisher