Mass Effect 3's ending will anger some of the series' fans, BioWare has admitted.

The sci-fi action role-playing game begins with the Reaper invasion of earth, and sees Commander Shepard embark on a mission to convince the various races to join forces in an attempt to fight back. It marks the conclusion of Shepard's story, which began with the release of Mass Effect 1 in 2007.

This, BioWare producer Mike Gamble told Eurogamer, puts pressure on the team to deliver a satisfying ending.

"We have a really talented team of writers. We go through iteration after iteration, making it the best and most satisfying we can," he said.

"It's going to make some people extremely happy. It's going to make some people angry. But that's part of it, right? To invoke the emotion putting some of these stories to bed will naturally bring up.

He added: "I honestly think the player base is going to be really happy with the way we've done it. You had a part in it. Every decision you've made will impact how things go. The player's also the architect of what happens."

Whether you're happy or angry at the ending, know this: it is an ending. BioWare will not do a "Lost" and leave fans with more questions than answers after finishing the game, Gamble promised.

"You'll get answers to everything. That was one of the key things. Regardless of how we did everything, we had to say, yes, we're going to provide some answers to these people."

Like Mass Effect 2, Mass Effect 3 lets you import your game save to continue your story. "If characters lived or died they'll be there or they won't," Gamble said. "Certain exchanges, certain romances will be different depending on your previous choices you made in Mass Effect 2.

"There are so many different places where we're reading certain plot states from the past that, without ruining any story spoilers, it definitely has an impact on the game."

Gamble said players will feel the impact of their decisions more keenly in Mass Effect 3 than they did in Mass Effect 2.

"Because a lot of these plot threads are concluding and because it's being brought to a finale, since you were a part of architecting how they got to how they were, you will definitely sense how they close was because of the decisions you made and because of the decisions you didn't make," Gamble said.

"You'll definitely feel it."

Mass Effect 3 launches on 9th March.