Fallout 4 is great. However it lost what made Fallout games Fallout.
The dull, bleak and ominous Capital wasteland of F3 had plenty to do, I use the world dull because of the colour tones used. You could explode a entire town, decide fates of dozens of individuals around you and get seemingly lost in post apocalyptic DC. The initial set up and time in the vault is executed in a way that makes you care more for your characters mission, the world seems much more lived in.
Then there is New Vegas, the Obsidian made masterpiece of a video game that will remain in my top 5 games for the unforeseeable future. The world-building, lore, highly developed setting and characters in addition to the impact your character can have on people and events around them is truly admirable.
Fallout 4 has awful graphics for it's time. The npc's are pretty boring and although they comment on events and their affinity for your player character, they lack true goals and personality other than likes and dislikes and the occasional mission. It is a shell of a fallout game and the story had potential to be one of the greatest video game stories ever made. The weapon variety is bland compared to previous games.
On the bright side the glowing sea is brilliant when you first visit, rad storms are a cool idea and the legendary weapon system is fun other than finding 6 legendary pool cues on humans and a explosive legendary pistol on a radroach.
Fallout 4 does not have the fallout vibe to it, it is too bright and colourful, their are hundreds of missions and side activities yet they lack memorability as do the vaults you can discover. The world features few references to previous games other than the few recurring characters, this makes our previous heroes seem irrelevant. Bethesda, you have made brilliant worlds, please bring back the sense of dread to the fallout universe. And WOW FIX THAT DOWNGRADED DIALOGUE LAYOUT PLEASE.