The first problem, I suppose, is one of etiquette. How do you pronounce his name? Is it "Xor," "Xor" or even, "Xor"? Myself, I'm not so sure, but I feel it's important to settle things in your own mind before wading in with the game.
It's a maze game. Controlling the mazes (all fifteen of them) is Xor, and your job is to reveal him by zipping through all the mazes and reaching his HQ. And while you're at it, collect all the masks too. Not very easy at all in fact. You control two different shields, and by switching between them, you can hopefully pick up all the little Xors. A monitor down the side of the screen will tell you where to find the masks, how many you have, and how many more you need to find. It also tells you which of the two shields you control. You have something like two thousand moves in which to get round the maze (not many when you keep forgetting where you are), but there's no time limit imposed.
Xor looks pretty good. The graphics are large and clear, and the game's very easy to get into. But I'm not sure that you're going to want to stay there. It's just a bit too clever-clever for my liking, and I must admit that I can only be impressed by the look of the thing for so long before I start to wonder where the gameplay went. I like the general idea, but there's no real excitement, you just keep plodding around the place. It looks good but Xor is let down by its gameplay.
Interesting-at-first maze game that becomes less ab-xor-bing as you go on. Good graphics, bodes well for the future.