Can I catch up on Chapters I may have missed after the three-week period during which they were playable?

Yes! Even if you miss multiple chapters, you can always jump back in and catch up with the rest of Neopia. Whether they may have contained minigames or Battledome challenges, you can still participate in all of the fun that comes along with a plot. You might miss out on some exclusive prizes, but you will still be rewarded for your efforts in other ways.