There’s a secret stage in the wonderful Tetris Effect – and it’s pure nostalgia fuel.
Tetris Effect has a Weekly Ritual system that is, effectively, a community goal. When it’s reached, new things appear in the game. The weekend just gone – Tetris Effect’s launch weekend – saw this community goal met and a “1989” stage that turns Tetris Effect into the Game Boy version of Tetris – complete with retro graphics and that music – unlocked.
Once the goal was met, this secret stage popped up within Effect Mode (the non-campaign part of the game) and was selectable from any of the modes that let you pick a stage – so, for example, Marathon.
Source: Eurogamer Tetris Effect players have discovered a secret Game Boy Tetris stage