Your goal in Grid16 is simply to stay alive as long as possible. You start out with 16 live mini-games, each recognizable as a video game archetype. Every few seconds, the current mini-game will pause, retreat into the background, and be replaced by another game at random. Your control method is always the arrow keys, but they act differently from game to game. Your objective changes constantly as well, but it almost always boils down to either touching something or avoiding something. The whole point here is simplicity.
To keep things interesting, a speed multiplier gradually counts up as you play, eventually doubling the pace of the game, tripling it, and more, with no limit in sight. When you fail at a game it disappears from the line-up, and when you've lost all 16, you're done. Have fun, and try not to have a heart attack.