I'm one of the game creators and this submission is not mine. I couldn't resist to upvote it though. As for the game getting boring I really hope you're wrong: most of the players find it very addictive and it will get better if more people will find adversaries online.

There's a real life game where you "assassinate" other people that has been popular with schools for decades: http://en.wikipedia.org/wiki/Assassin_%28game%29

This is essentially a computer version except with some complexities like hit points and damage taken from modern computer games.

So I really can't see it getting old quickly since it is based on a successful concept already. Indie game developers are often told to start from these successful concepts since it reduces the user research costs and rewriting.