When Doom was announced, I was bit sceptical, because their marketing was targeted towards multiplayer. We knew little about singleplayer and we wanted Doom for singleplayer, right? I played beta and was really dissapointed, so I dropped this game for a long time. However few months ago, I bought it for a few bucks with and was nicely surprised by it.
Doom is one of the most energetic games i have ever played. You do not regenerate any HP by standing still. If you have low HP, you have to finish more enemies by your brutal melee attack, because when you finish any monster by melee attack, the monster will drop green balls, which regenerates your HP. So standing still = 100% death
Graphics are amazing and monsters are interesting and refreshing, but they are still same when you are coming to an end. Level design is very well done and every single level has plenty of secrets for „trophy hunters“ and challenges for better abilites. When it comes to a story, there is absolutely no story, but you will not care, trust me.
At the end of the day, multiplayer is good too. It is not the best thing you have ever played, but it works. I personally spent about 10 hours on it, and maybe I didn’t like it in beta, because i played it like COD, and not like i should. So if you do not know what to play, Doom is a really good choice, with quite long singleplayer campaing and „not for everybody, but solid“ multiplayer.