Lava gameplay
Lava is the first world after School, and it introduces the blocked cell mechanic. Obstacles sit on the board like cooled lava flows. Your pieces cannot land on them, and sliding pieces (rook, bishop, queen) cannot send beams through them. Knights jump over obstacles as usual, which makes them especially valuable here.
Lava introduces obstacles. Blocked cells are squares where you cannot place a piece, and they stop sliding beams (rook, bishop, queen) from passing through. A rook on one side of a blocker cannot light targets on the other side. You have to route your coverage around the obstacles, which turns straightforward puzzles into spatial planning problems.
Multi-piece puzzles with rooks, bishops, queens, and knights
Starts with a single rook on a 6x6 board with one or two blockers. By the end you are placing four pieces on 8x8 boards with complex obstacle layouts.