He won the player of the tournament at the World Cup in 2014. He had a big impact in the group stages, scoring in all 3 games, including an excellent goal in the last minute to beat Iran (can only beat who you are up against and all that). He had a more disappointing knockout stage but he's held to such high standards that some people ended up disappointed in him by the end of it.
I can't ever remember Cristiano Ronaldo doing a massive amount in any World Cup, certainly hasn't ever been voted player of the tournament. People will mention the Euros win in 2016, where he did win the player of the tournament in that, however, Portugal must be contenders for the worst winners of any international tournament with that win, drawing all their group games (Ronaldo only scored 1 in that), and relying on extra time or penalties to get through the next 2 rounds (he didn't score in either game). Scored in the semi and went off in the final after 25 mins. Was hardly a massive influence throughout that tournament, when you consider how much of an impact he has in the CL.
No doubting he's a phenomenal player though.