If you liked FO3 you’ll like 4.
It’s a lot stronger mechanically than 3 or NV - shooting is a lot less janky and the gun customization adds some great emergent quests.
The Boston of FO4 has its moments - a certain duck pond stands out to me in particular - but aside from Nick Valentine the questlines are largely forgettable.
Still, the core game loop is a lot of fun - go here, blow stuff up, scavenge bits to upgrade your stuff.
As a longtime Fallout fan (came for the isometric apocalypse, stayed for the 3D googie architecture) I still put 80 hours into FO4.
It’s a good fuckin’ game. It’s just competing with the legacy of a lot of other great games in the series.
Mechanically - both games are puzzle games in the same rough 3d-platform-puzzler vein as Portal. Instead of solving puzzles with teleportation however, you’ve got laser beams and force fields.
On a more metaphysical level, the first game is a philosophical investigation of what it means to be human - to be alive and an individual.
The sequel is a meditation on what makes societies succeed or die.
Both games are fun, the puzzles are just hard enough to be interesting with a sprinkling of well-hidden secrets. But the real reason to play The Talos Principle is if you’ve got an interest in philosophy - the storylines are deeply interested in asking some very big questions. … and they don’t provide answers either - the game poses questions and allows you to answer as you see fit.