It really doesn't matter which one you pick, since they are both stellar games.
MK is great for the online and multiplayer. It is also a great game for quick 15 minute games.
MP3 is epic and full of great visuals and excellent puzzles. Whenever I played it, I had to set aside at least an hour at a time. Usually 2 or 3 hours.
If not now, eventually you MUST buy both.
In the absence of evidence to the contrary, always assume you have the upper hand.
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