This is the description on the BGG listing of the 4 promo tile set:
The tiles provide more aesthetic variation in the platform artwork. Before you add all four new tiles to the game, you are encouraged to first remove one tile of each platform type from the base game.
From what I understand, this just replaces 4 original platform tiles, without any rule changes or additions.
The Dice tower and Game Boy Geek tiles have do description whatsoever.