Doesn't get old!
Contra is not really a hard game, but its not something that you'll breeze through every time... its a game that takes trial and error to discover enemy and turret placements so that you can improve your times, scores, and plain skill at the game. Not to mention that if you are having trouble beating the game, there is always the classic 30 Lives cheat code. The achievements are also worthily put in, and I couldn't think of better ones myself. I mentioned this before, and it is definately the downfall of the game; the online co-op is incredibly broken... many times team mates will be stuck on completely different parts of a level, or on a totally different level... and he/she will be constantly dying on your screen, causing you to take the adventure into your own hands.
Either way despite its harsh flaws, it is an encumbersome experience that shouldn't be missed by anyone who has or has not played the Contra games before at only a few button presses away in the XBLA.