2013 PlayJam GameStick devices have a all-around rubber coating, and the controllers have a rubberized bottom. After 11 years, the coating's chemicals dissolved, leaving a sticky mess that sticks to your fingers when touching it.
It is possible to get rid of the coating by rubbing it off with Isopropanol (Isopropyl alcohol), an old sock and a pair of surgical gloves.
The rubber coating was mentioned in the 2013-07-11 Kickstarter Update #36: The Golden Sample:
- Put a rubberized coating on the bottom of the controller. This gives the finish a really nice quality feel.
- Used a rubber coating on the GameStick so that it did not scratch when inserted in to the controller. It really looks and feels fantastic as a result.