The one thing that surprises me about most comments is the confusion and lack of understanding and appreciation of the songs meaning and subject matter.
It is always dangerous to second guess the meaning of song lyrics but in this case I felt the lyrics were quite self explanatory simple and straightforward and I did not think there would be much controversy over this aspect of the song.

Now the singer might be a jilted lover as some people think. That is possible but he might just as easy be a downtrodden person who folk did not think would amount to much. Does not matter either way or who he is saying it to for that matter. He is just saying defiantly "Screw you I did make something out of my life contrary to what you thought. Whilst some people shoot for the moon I shot the sun." In other words he surpassed his target a million fold. The song is a declaration that he will not be beaten and will win in the end despite him being seen as a failure.

Re the card references I do think that he is referring to the game called hearts. Shooting for the moon is a term in the game used to mean winning all the hands to score bonus points against all your opponents as opposed to losing the hands which is the main object of the game. The queen of spades is the danger card worth the most points so is the most important card. Understanding this game and its quirky rules is not important and is of little consequence. Nuff said if we just know that he has a winning hand, he knows how to play it and is playing to win.
There are many very clever little plays on words and metaphors throughout this song. If people do not "get it" then that is again unimportant more the fault of the listener than the fault of the writer.
As was stated there have been many big hit songs where we have not got a clew what the lyrics mean. Most pop and rock songs are more concerned with the music and arrangement. Audiences tend not to do deep analysis of the lyrics. That said this song's lyrics IMHO stands up to any analysis.

I would like to hear more comments about the music structure and performance. Lyrics are only half of the song...if even that. For certain genres lyrics contribute only a tiny percentage of what sells.