That was entirely Valve's intention if I'm not mistaken. The engine is still source, but they seem to have maximized the potential of the engine seeing as how much better csgo looks than css, while still having that source engine look. They wanted to keep the counterstrike gameplay as is, because that's whats worked. Interviews with Valve devs have consistently shown that they're not going to add cover mechanics or iron sightings and other stuff that the rest of the FPS's in the market have, because that's not counterstrike. I'm really looking forward to this because they added some new weapons, grenades other than smoke/flash for added utility. And I think their target audience for this is both 1.6 and CSS. They mean for this to succeed both of those and the gameplay will be a blend between 1.6 and CSS. Because right now, 1.6 and CSS play somewhat differently in terms in shooting, physics, registry, etc etc. But CSGO is sposed to somehow blend the two in such a way that they mean for it to totally combine and succeed both 1.6 and CSS. Idk how the hell that's gonna work, that's what I'm looking forward to the most.