While I agree that if you take the VR away, it would take away from the game a little, don't get me wrong, it would still be a really good platformer, just not as fantastic as when in VR.
The use of the 3D space, level design and the sense of presence the player has in VR is like nothing else. It really hit for me in World 2-1, when the level grows upwards on a beanstalk high into the sky and wraps around you in places, so you have to navigate Astro above you or below you and around the back of your head, physically turning around to see where Astro is. It's very cool.
The sense of scale is so impressive too, with the beanstalk towering above you, same goes for the bosses, they look huge in VR, something which you definitely don't feel when watching it on a TV.
Player interaction is also something VR adds over playing on a TV. Having the player be a physical presence in the world and having levels that require you to headbutt walls, dodge enemies that target you, not Astro and use the DS4's tools to help Astro progress through the level, is all extremely well implemented and this along with the charming art style and level of polish, all add up to make Astro Bot a unique and bloody brilliant game.