Currently, we have at least 12 questions relating to the game 2048. I think it would be worth creating a 2048 tag, as there are a non-insignificant number of these questions now. We have tags for other games, like chess, boggle, scrabble (many of which have fewer than 10 questions), so there is precedent for these sorts of tags existing.
There is a sliding-puzzle tag, which includes 2048 (this is stated clearly in the excerpt). However, less than half of the 2048 related questions use this tag, and it's not very "discoverable" to those writing questions involving the game.