WIP The Chase Dashboard V2.1

WIP design for my friend's social scavenger hunt app called The Chase.

Upon logging in for the first time, a user will see this dashboard list of available scavenger hunts.
Hunts are rated with a general star rating as well as a difficulty rating, indicated by color coded icons in the top right corner of each card (shown here, yellow, indicates medium difficulty). Each card also shows which of your friends are participating in a hunt.

Challenges I'm tackling are:
1. How to clearly represent the rating data. I think there could be some confusion around the magnifying glass icon. My original thought was that scavenger hunts involve searching for clues, and the more difficult it is, the harder you have to search.

2. Gracefully incorporating sorting & filtering functions without forcing too many steps, menus, and points of navigation on the user.
Here is one solution in which I include a "Sort by" spinner in the top right corner.

Please share your feedback & critiques.