Nintendo tweeted an extensive list of upcoming Wii U releases, but the company still isn’t getting specific about Super Smash Bros.

We know that Super Smash Bros. for 3DS goes on sale Oct. 3 in North America, but when it comes to the Wii U release of the four-player mascot fighter, we don’t even know the month the game is coming. In a post to Twitter this morning, Nintendo of America once again said that Super Smash Bros. for Wii U is due out this “holiday” — and that’s it. As days go by, the lack of a solid date for what is supposedly Nintendo’s biggest game of 2014 has some fans worrying about a delay into 2015.

Smash Bros. is one of Nintendo’s biggest games. It has characters from different franchises, like Mario, Zelda, and Metroid, battling it out in a chaotic multiplayer battle. The series first debuted on Nintendo 64, but it found an even larger audience with the GameCube version, Super Smash Bros. Melee.

The Wii’s Super Smash Bros. Brawl, which debuted in 2008, sold 1.4 million copies in one week in the U.S. That made it the fastest-selling Nintendo of America game ever at that time. With the Wii U in need of any hit it can get, Smash Bros. is a particularly important title.

Super Smash Bros. for Wii U isn’t the only game with a vague “holiday” release date that Nintendo says is still coming this year. The publisher also hasn’t provided a date for puzzle platformer Captain Toad’s Treasure Tracker, but that’s probably not something Smash fans should take as a comfort. Nintendo actually delayed Captain Toad into 2015 for the European and Australian markets.

We’ve asked Nintendo for more information, and we’ll update this post as we learn anything new.

Super Smash Bros. is one of the most-important Wii U games this year. While the 3DS version is likely going to win over some fans, Smash’s large, dedicated audience is more excited about the first high-definition entry in the series. The game drew large crowds at the Electronic Entertainment Expo tradeshow in Los Angeles in June, and Nintendo’s first invitational tournament for the game drew a crowd of 2,000 live spectators to the Nokia Theater in L.A. during the E3 event.

With the Wii U performing better thanks to the successful release of Mario Kart 8, Nintendo needs Super Smash Bros. to maintain the console’s momentum through the holidays. Company president Satoru Iwata told investors earlier this year that he expects Nintendo to sell 3.6 million Wii U systems this fiscal year, which ends March 31, 2015. Getting Smash Bros. out before the end of the gift-giving holidays will likely going to play a big part in realizing that goal.

Nintendo first announced Super Smash Bros. for Wii U on June 7, 2011, which is 1,183 days ago, according to Wolfram Alpha. As Ars Technica pointed out last month, no first-party Nintendo game has had a longer period from its first announcement to its eventual release in recent history.