Brazil 2 - 0 Costa Rica
Costa Rica is a great team, but I see Brazil as the strongest team in the world cup. Brazil has a lot of great players and should be using in my opinion Roberto Firmino as starter
Switzerland 1 - 1 Serbia
Both teams are strong. For me the swiss are better but not good enough to beat Serbia. Both teams have offensive defenders so I don't see any of the teams being able to get a clean sheet
Iceland 1 - 0 Nigeria
Iceland is strong, they lack in my opinion good strikers though. For me their midfield is their best asset. I don't see Nigeria being able to score against Iceland
Brazil you're right. Iceland with not a funny day. I hope now for my swiss friends.
Best regards
sportfrei