In a recent interview, Bach states that they’re aiming for a full year of play if players want to unlock everything. Bach said:

“You don’t have to play through the whole game to unlock a new thing – you’ll actually unlock things for each specific weapon and kit. On the other hand if you want to explore the full unlock tree, there’s plenty of things for you to do – we’re aiming for a full year of play for those who really want to unlock everything.”

Of course, a “year of play” differs from player to player. Since it’ll take 400 hours to unlock everything on all kits, that’s just over an hour of gameplay per day for 1 year. We’re sure many will be playing a lot more. On top of the unlocks, there are awards and DLC which will surely provide incentive for players to keep playing a long time after the release. Not to mention the stats tracking and fun gameplay — after all, it’s been 6 years since the release of Battlefield 2 and there are still thousands of active players.