The Oranje have impressed so far after progressing as Group B winners with victory in all three games, including a shock 5-1 dismantling of Spain in their opening encounter.
WORLD CUP SOCIAL HUB
Keep up with all the latest news from Brazil and get involved in the debate on Twitter with our new World Cup Social Hub
"They are dangerous opponents," the Bayern Munich attacker told the Times of India.
"Especially when the match is being played in Brazil, a country more familiar to them. They are fearless opponents and proved it against Brazil in their group league match [a 0-0 draw].
"It's really been an unbelievable start for us. Before the World Cup, if you had said to me that we shall win all the three matches of the group, I would have not have believed you! But that's football and we did almost everything right to qualify for the round of 16."
Robben missed a golden opportunity in defeat to Spain during the last World Cup final, but was pleased to score a brace past Iker Casillas and go some way to making amends in this edition of the tournament.
World Cup Infographics
Uncover the statistics behind the World Cup with our new Unibet infographic series
"Then we played a second half that was almost like a dream performance. As if, we could do whatever we wanted to. That was the most pleasing part of that performance.
"It was satisfying. My goal gave us the lead and we were unstoppable after that, scoring goals at will almost. Scoring five goals against the world champions is something we shall never be able to forget."