Road to College- Anyone on this path before?

Hi, I'm an A level student in Singapore. Anyone knows what it takes to get into the top universities in the United States such as Harvard, MIT, or any other best colleges? I have a desire to get into one of them. At the singapore 6th grade, the standardized nation wide testing decreed I'm part of the top ten percent of the whole batch of students. Unfortunately, my teachers at secondary school failed in their duties, causing me to churn out some disappointing results. At least they were to me. But still better than the average students. However, after I got into pre u, I think I'm getting back my momentum like those I had during grade school. I'm taking A levels soon and I'm quite confident about this. I need to get into a top university. My cousin has been very cynical since I got my test results( the one at 6 grade). It is perhaps due to the sour gs syndrome since he got bad results for the same 6 grade nation wide exam. I need to get into a top university to shut his sarcastic remarks up and that of my very lazy pre u physics teacher. Also, I need to get into a top uni so my parents won't get that disappointed. Look, I'm very serious abut this so anyone able to help?