It's not really optional at all. If you skip an event and don't collect all the characters then it's likely it will hurt you in the next event, or in another one they are planning. They way they set up this game, you either have to really play it to it's fullest or you'll constantly be locked out of stuff "down the road." So, personally speaking, I would have preferred more of a break between events since I'm not ready to stop playing altogether, although the stress of back-to-back timed events is pushing me in that direction. Just one player's perspective.