Autumn season challenge

I collected all 10 artifacts & after that nothing happens. The objective to collect them all is done and there's no other objectives & still at level 9. So disappointing. Just letting you know. Here's a list of all 10 ring artifacts: Infinite Loop, Angel Wings, Twisted Root, Floating Island, Sky Clasp, Demon Claw, Ruby Shard, Caves Maw, Mystic Rocks & Idol's Curse.

In addition, here is a list of the Christmas-themed artifacts added in the December 2013 update: a candy cane, present, wreath, stocking, and a piece of holly. Once you collect all of Christmas artifacts, your character gets to wear a Christmas hat, and you can play as Santa for 60 gems.

Further addition: there are 5 Valentine's day related artifacts available in chests in a recent update as well.

The Christmas artifacts are not rings, they are various Christmas-related items (sprig of holly, etc.) I don't think those Christmas artifacts are available in the game anymore as I haven't seen them in a while. They had Valentine's artifacts for a while as well. But neither of those aren't needed to complete the "all the rings" objective and the ring artifacts are definitely still available as of the current (post-Valentine artifact) update.

So for completing the "all the rings" objective, it's actually good that the Christmas and Valentine artifacts aren't around anymore, as more of the artifacts you get from the chest are going to be rings. If your experience is like mine, you will get many copies of some of the rings before you finally get whatever last missing one you need to complete the objective.