Sometimes. Either your internet connection or your computers processor is slow, or both, and cause you said epic I assume it's also caused by lots of objects or movieclips on the game window at the same time.
But the thing that bothers me most is your question. Cause it doesn't make sense. Try: "Does your computer lag and mess you up when you are playing an epic game?" Please try to make sense when asking a question.I'm just trying to help. :3
Ok well your internet connection is probably slow. Although I encounter a problem on a separate comupter I use where the processor is slow. If that's the case I think all you can do is wait, or choose a different game.
Try keeping only that window with the game open. If you have some sort of other application going on in the background it could do something big and lag the game.
First of all, internet connections does not matter! THe game is downloaded beforehand, so no lag is caused by slow internet. Second, there is a forum topic that shows you how to prevent lag, find it. Third, upgrade your box!