Tomb Raider has a multiplayer aspect so you have a reason to stay in Lara Croft's world a little longer, according to Eidos Montreal's Daniel Bisson.
Speaking with Eurogamer, Bisson said one motivation for adding multiplayer to the traditionally single-player franchise was to exploit the richness of the game's setting.
"With single player, there's a start and there's an end. And you have some games with a rich universe, and you think you want to stay there forever and then it ends. You want to stay in that universe - there are some games like that," he said.
"One of things that was pitched was can we make that Tomb Raider universe persistent? We wanted to do that, and we explored new maps and new types of gameplay, and for me that's very meaningful - taking that world and making it persistent."
Bisson also said Crystal Dynamics pushed for a multiplayer mode because Lara Croft and the Guardian of Light, an isometric co-operative affair, showed the Tomb Raider fiction isn't sacred to single-player games.
But the developer admitted the multiplayer side of things isn't essential, and didn't pretend that what Tomb Raider does is particularly original.
"We don't have to have multiplayer to have a successful single-player. I do agree that it's not critical to do that," he said.
"Let's be honest, it's not oh my god this is a revelation. It's a first step," he added.
"If it's powerful, if it works well, we're going to continue and we're going to build on that. For us it's about making an experience that's a little different. It's not ground-breaking, but it's fun, and it's Tomb Raider."
Tomb Raider is due on PC, PlayStation 3 and Xbox 360 in March.