Hikari for Windows

Hikari's interface is restrained and the concept is elegantly simple, and at first we thought it was a kids' game. However, the Hikari concept evolves into a brain-stretching challenge that, at its highest levels, is frustratingly difficult.

To complete a level, you must illuminate all the bulbs on the board. Most of the early puzzles consist of the two most common bulbs, 25-watt and 60-watt. When clicked, the 25-watt blue bulbs activate themselves and the four (if any) bulbs at each 90-degree angle (von Neumann neighborhood). Similarly, the 60-watt bulbs control themselves and the four bulbs at each right angle, but they also command the four corner bulbs (Manhattan neighborhood). Bombs, turnstiles, and swappers spice things up.

The demo version contains 30 puzzles out of the 200 in the full version. The first boards are painfully easy, but everything after level 10 is moderate, levels 20 to 30 contain some real doozies, and the full game gets insane. Like most great games, Hikari is simple to learn and easy to start playing, yet extremely difficult to master. If you're the obsessive type and need to finish every single level, be warned: This lightbulb game may just burn you up.