Today’s featured promo on MacUpdate offers Lumen for US$4.99 (50% off, retail $10). “Lumen is a simple and beautiful puzzle game. The objective is to light up checkpoints by bouncing, coloring, and maneuvering a laser beam through obstacles. Although puzzles may seem easy at first sight, they can be quite a challenge. The careful attention to detail and the colorful graphics make Lumen a joy to play. An online database of puzzles ensures that new puzzles are constantly added.” Lumen requires Mac OS X 10.2 or later.