Cheese method
Press Ctrl+Shift+I in-game to open the console, and go to the Console tab.
Start the first level in jigsaw puzzle mode.
Run the following code, click and release a piece to register the win, and restart the level (press 0 for a shortcut).
Repeat the same process until unlocking all achievements (one per win). You can press the up arrow key to repeat the previous console command, making it more convenient to use one hand for the keyboard and one for the mouse while doing this.
var milestones = [
1, 3, 5, 7, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90,
100, 110, 120, 130, 140, 150, 160, 170, 180, 190,
200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300
];
var state = Game.PieceFunctions.prototype.hostState;
var allPieces = state.allPiecesArray.flat();
PUZZLES_COMPLETED = (milestones.find(ms => PUZZLES_COMPLETED < ms) || 1) - 1;
allPieces.forEach(function (piece) {
piece.position.x = piece.data.homePositionHitCircle.x + state.piecePositionBoundaries.left - state.pieceCanvasDimensions.width + 16;
piece.position.y = piece.data.homePositionHitCircle.y + state.piecePositionBoundaries.top + 48;
allPieces.forEach(function (p) {
if (p !== piece) {
p.data.connectedPiecesArray.push([piece.data.arrayCoordinateX, piece.data.arrayCoordinateY]);
}
});
});