Sliding block puzzle on a 7x7 board with the goal being to move the blue 2x2 piece to the green exit on the right hand side of the board. There are 5 types of pieces: 2x2, 1x2, 1x3, 2x1, and 3x1. The 2x2 pieces move left, right, up, and down. The vertical pieces move up and down. The horizontal pieces move left and right. Diagonal moves are not allowed. Pieces can only move into unoccupied board squares. This first version contains 10 puzzles at each level of difficulty, from 15 to 299. The difficulty level is the minimum number of moves to solve the puzzle. All puzzles are unique - not sharing any board positions with any other puzzle. Solved puzzles are stored in local storage and are not displayed again.