It's such a simple, wonderful game. There's a few key details that I think distill it into a masterpiece.
1. A three year old could learn to play in minutes. Simple to learn, harder to master.
2. Your best runs last the longest, so as a fraction of your overall time played your better ones are the biggest portion. You remember winning a lot of the time.
3. It's absolutely pure animal player vs player. There is no chat, no real teams, no organization, just outplaying one another.
I hope future game makers learn from this.