No Man's Sky is a change for pace for most gamers who like the action-oriented RPGs, following the examples of 'keep exploring' kind of game play as seen in 'Myst' or 'Spore' before.

Videogamer says:
No Man’s Sky fails at a fundamental level; it’s designed to be played endlessly but in the end, it simply doesn’t have the stamina to sustain itself. Which is a massive shame, because it has a lot going for it. It’s often very beautiful. It has an infectious attitude about it
 

Gamespot says:
If you only concern yourself with exploring, mining, and buying goods, you may burn out on No Man's Sky early. Atlas' observations regarding these pursuits are apt, but even if you recognize these activities as shallow, they could be better with added depth and improved mechanics.
 

Eurogamer says:
The game was built to be infinite, and in practical terms it is. It's an endless, edgeless field possibilities. And yet it needs an endpoint, or at least a set of waypoints, to give purpose to your journey - to give you somewhere to be headed.


Insertcoin says
I understand why many would be bored with No Man’s Sky given players used to consuming a diet of action-oriented RPGs, but saying No Man’s Sky is boring is like saying a leisurely hike through the woods or a cross-country drive is boring just because it isn’t bungie-jumping or street racing.