Auralux (iOS|Android) on its surface is a beautiful and simple strategy game, but it quickly gets very challenging as you progress through levels. Your job is to conquer suns, and ultimately two AI-controlled teams using a single type of unit.
There have been other similar strategy games for mobile devices, but none that kept the gameplay so incredibly simple. When you start out, you have one sun that is producing an army per second, as does each other team. But before you rush to attack another team, you'll want to conquer gray, uninhabited suns by sending your armies. Once conquered, the gray planet will change to your color and start producing armies you can use to attack others. Suns with rings around them let you upgrade to produce more armies per second, making them the most powerful suns on the game board.
You have a couple of ways of selecting and sending your armies to attack. You can either touch and drag to draw a circle around your armies, or simply touch the sun where your attacking force is. From there, just touch the sun you want to conquer and your armies will slowly begin closing the distance to the enemy sun. This game isn't about fast reflexes -- Auralux is a game of strategy and figuring out when is the best time to attack.
The gameplay is simple and addictive, but also forming a big part of the draw of Auralux for me are the brightly colored graphics, ambient music that never seems to get old, and various sound themes you can pick from in the game. There is something almost zenlike with the pacing of this game and the bright colors and audio add to the experience.