Features in games that have been done to death:
Graphics: - Seriously, when was the last time they made a game without graphics? Text games back in the day didn't have to have graphics to be fun. Why not have a game with just sound and no graphics? That'd be original, at least.
Music: - This little dinosaur is as old as time itself, and yet we're still dragging it around with us. Why can't we get a game that plays that noise dial-up modems make instead? Or maybe the sound of alleycats fighting?
Input Devices: - Seriously? Why does every game in existence rely on input devices? The Kinect even uses a huge camera doohicky that interprets your movement. Sure, the input device itself changes now and then, but it's old hat. We need something new.
Lack of Pain: - With the exception of really horrible games like Atari's E.T. and Superman 64, there are no games that cause any measure of pain to the player as a gameplay mechanic.
Polygons: - You know, polygons had a great run back when they first came out, but now it's just old hat. We've seen it before, and you're not impressing anyone no matter how many of them you can fit on a screen. It's right up there with the next one on the list...
Pixels: - HO-LAY-CRAP these are overused. Seriously people, it's 2012! Why are we still using relics from the prehistoric period of the computer era?? Get with the program!
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All kidding aside, the point I'm trying to make is that it doesn't matter whether or not it's been done before, it matters whether or not it's done well.
Please try to remember that before flailing your arms and screaming about WoW clones.