Is the Intel 620 that could of a video card? I didn't see a dedicated card listed on Razer's website. I would hate to run anything above 1080p on integrated.
The Blade Stealth is not a gaming laptop on it's own, it's a notebook. If you wanted to get any serious gaming done on it you could buy the "Razer Core" that is mentioned in the article. It is an enclosure that you can use to attach a desktop sized graphics card to your laptop. This gives you the flexibility of a fairly light notebook you carry around with you and then plug in when you're at home for gaming.
Or if that sounds like too much hassle you could get the Razer Blade which has a gaming grade GPU. Or just a gaming desktop!