According to id Software, single-player campaign of DOOM will be around 13+ hours, not a short one as we all probably expected.
.@Unreal389 The difficulty level plays a factor, but folks playing at the office average 13+ hours in the campaign
— DOOM (@DOOM) 11 Şubat 2016
Thanks to Unreal389 for asking the right questions. Of course it depends how you play the game. If you like to wander around and see every detail, you will spend much more time while playing Doom.
FPS multiplayer specialists Certain Affinity is working with Doom team developing multiplayer modes for Doom. You can pre-order Doom now or wait untill May 14.