Nintendo apologized today for failing to include same-sex relationships in its life simulator game Tomodachi Life.

The statement, posted to its website, reads: "We apologize for disappointing many people by failing to include same-sex relationships in Tomodachi Life. Unfortunately, it is not possible for us to change this game’s design, and such a significant development change can’t be accomplished with a post-ship patch.

"At Nintendo, dedication has always meant going beyond the games to promote a sense of community, and to share a spirit of fun and joy. We are committed to advancing our longtime company values of fun and entertainment for everyone.

"We pledge that if we create a next installment in the Tomodachi series, we will strive to design a game-play experience from the ground up that is more inclusive, and better represents all players."

In Tomodachi Life, players bring their Nintendo avatars, called Miis, onto a virtual island where they can become friends, rivals and more with other Miis — including husband and wife. However, it is impossible in Tomodachi Life for relationships to be formed between Miis of the same gender.

The game launched in Japan in April 2013 as Tomodachi Collection: New Life as a sequel to the Japan-exclusive 2009 3DS title Tomodachi Collection.

The company came under fire this week for its response to requests for a same-sex marriage option to be included in the game. LGBT advocacy group GLAAD said Nintendo's stance on the issue was "not only sending a hurtful message to many of its fans and consumers by excluding them, but also setting itself way behind the times."

Writer Samantha Allen wrote in an opinion piece for Polygon that said Nintendo's move to not allow same-sex relationships in the game puts it on "the wrong side of history."

Update: GLAAD CEO and president Sarah Kate Ellis said in a statement posted to GLAAD's website today: "Nintendo has taken a first step, but if the company's longtime values are rooted in 'fun and entertainment for everyone,' then it needs to catch up to peers like Electronic Arts, which has been inclusive of LGBT gamers for years."

Publisher EA is known in the games industry as a vocal supporter for the LGBT community.