We added a neon pixel heart design to our shirt store. It is based on one of the first game objects that you will see when playing Episode 1 of the story mode:
On further note: one of us was at the Global Game Jam in Berlin as an organizer.
The theme was a snake biting its own tail and we made a tiny level referencing it. Too late for submission though. ;)
The video also shows the recently added game over screen menu (no more abrupt returning to the level selection) and a new, simple background for the editor.