Is it a Sin to Play Games When I Should Be Sleeping?

     I have "Words on Tour" on my new smart phone which I enjoy, but which can also be a little bit obsessing as enjoyable and challenging things can sometimes be.
     I awoke in the night and knowing that today is No Alarm Clock Saturday, but also knowing that I seldom manage to sleep in much past my normal alarm time and often even wake up earlier, I still picked up my phone to play "for a few minutes." 
     You know that those few minutes can go on a little longer than intended or than we realize.  Also, electronic devices can wreck havoc with sleeping because their light or something affects our melatonin.   We are told to avoid screens time for  30 minute or an hour or so before bed.   R-i-g-h-t !  like books, you know the kind with paper (non-lit) pages) are safer!  How many hours of sleep have I lost to books??!!
       But back to the question.  Is it a sin?  It might be foolish.  Ok, it probably is foolish.  Is it a sin to be foolish?  It certainly is not god-like and supposedly we are trying to become more like God.
       What is sin?
       I asked my church.  That is I went to the lds.org website and typed the search "What is sin?".  "To commit sin is to willfully disobey God's commandments or to fail to act righteously despite a knowledge of the truth (see James 4:17)."
        I almost felt relief.  Except we are commanded to take proper care of our bodies and " retire to thy bed early, that ye may not be weary; arise early, that your bodies and your minds may be invigorated” (D&C 88:124).
         Among the other answers to the question was this article which I find encouraging (not encouraging to play games at night, though)  "Sins and Mistakes"  Mistakes, even stupid mistakes (are there smart mistakes?) are not sins. (But when we know better it's not a mistake, right?) In this article,the Prophet Joseph Smith, Jr is quoted as saying, “What many people call sin is not sin.” (Don't be so hard on others.  and probably yourself.  We are not authorized to judge others, anyway.)  That same article says, "A fool is a fool, not a sinner."
         Ok, honestly, I don't know if playing games when I should be sleeping is a "sin."  Not a great idea.  Certainly not the worst sin I need to worry about having committed (wouldn't that be nice!!).  But probably not a "sin".  Should I repent of it?   I don't suppose that it would hurt and I absolutely need practice at repenting.  Why we (that is to say I) do not repent is another topic worth considering (unfortunately often).
          However we are now heading to another question which is, "Is blithering on in my blog when I have more things to do than day (and energy) to do it a sin?"
          I am now going to go get some laundry started (unless someone has beat me to it).