The first time I experienced a game using the light of day to influence things, it was an approximation of daylight in Pokémon Silver. You input your local time into the game when you start it and the cartridge itself would track it like any other digital watch, affecting Pokémon availability, day and night effects, and more. It was pretty cool, but it was still an approximation.
Then, I heard about Boktai.
In Boktai: The Sun Is In Your Hand, the cartridge has an actual sensor that sticks out from the GameBoy Advance so it can detect sunlight (although a UV lightbulb could spoof it). In-game, you're a vampire hunter, and the sunlight charges your weapon, making it safer to be out hunting. There are methods to collect small power-ups to charge your weapon without sunlight, but ultimately, you will want that sun when you fight a boss. When I found out about this game, I was blown away. This is innovative gaming.
There have been other video games since that have used synchronized day and night cycles to your time, but not a lot that have used actual light itself. On the other hand, tabletop games have been exploring light as a mechanic in interesting ways for years.
Ten Candles is played with ten tea light candles that provide the mood as well as act as a game timer.
Shadows In The Forest is played in the dark, with a central light casting shadows from some of the pieces that effect gameplay.
Vampire Hunter has a coloured light in the center of the board that changes colour based on if it's day or night in the game.
In the Exit game series, there are puzzles that require you to hold parts of the game up to the light, seeing through and merging multiple images into one.
I'm also reminded of old-timey alarm clocks, which were carefully measured candles with nails in them. When the candle had burned past a certain point, the nail would fall and hit a plate, making a loud sound and waking the person up.
What other mechanics could tabletop games incorporate revolving around light? Here's a quick brainstorm.
I don't know about you, but my mind is going wild thinking about this.
What would you use light for in a game?