I found this note on Twitter about some extras for the Incredible Machine...
I think you get an extra component to build puzzles, a Leprechaun. Also I think this is an easter egg of the game, it's not something the galaxy does. You can try to set your computer date 2 days before and see if it appears again
Well, I don't know what appeared or if there appeared anything at all. So that doesn't help.
But I think too, that there could be some hidden Easter egg.
I never played the game before (backlog) and didn't play it long enough now, I might have not noticed any changes.