In Califer Games' simple yet gorgeous little puzzle game Spirits of Elduurn, you control two excitable little spirits who think they've found a new home, only to discover it's chock full of nasty demons made from dark energy, which has happened to me at least twice before while house hunting. Using the [arrow] keys, which moves both spirits at the same time, your job is to guide your two spunky critters around the level, picking up all the glowing sparks and then moving your light spirit into the demon to banish it. The problem is that while both your light and dark spirits can pick up the sparks, only the dark spirit can cross the purple voids, and will actually slide across all adjacent ones in the direction you move. If the light spirit touches those voids it'll be destroyed, and if either spirit touches the Swirling Red Level Boundary of Doom (tm), they'll vanish, so you need to plan your path to make it through each level safely, and in as few moves as possible. Press [M] to mute, and [S] to skip a level when the prompt appears.