Campbell has played a key role in leading the underdogs to the quarter-finals in Brazil, and he believes that playing on the biggest stage is bringing out the best in him.
"This is a new level for me," the Arsenal forward, who is expected to be included in Arsene Wenger's plans for the first time next season, told FIFA.com.
"This is the World Cup and there's nothing bigger. I want to perform here. I want to score goals and help the team any way I can. Just because I'm young doesn't mean less is expected of me."
Costa Rica take on the Netherlands in Salvador on Saturday night.