There are many stadium-style entertainments, usually celebrating prominent local people and culture, a lot of music, dancing and marching, with promotional slots for various sponsors; traditional local food is consumed. As part of a recruitment drive for the armed forces the National Anthem is played. Occasionally some big strong men run around sometimes chasing, sometimes directly crashing into each other. There is a ball somewhere - this is the 'football' after which the spectacle is named.

It is a single game. It is also hard to explain clearly in writing. There's a field. The object of the game is to get the ball to your end of the field. When you do, you score points - it can be anywhere from 1-6 points, depending on how, exactly, you got the ball to your end of the field. The other team is, of course, trying to stop you and get the ball to their end of the field. Unlike soccer, it isn't continuous play. The game stops and starts very, very frequently.

I guess that our American friends will be able to answer this when they wake up. But I would say no, we wouldn't often say "an American football match". We would say "a[n American] football game". Each game is divided into two "halves" and four "quarters", although these are not very important because the game stops and starts many, many times. If we have already used "game" several times, then we might say "match". An example: the Wikipedia page on American football (https://en.wikipedia.org/wiki/American_football) uses "game" ninety times and "match" four times. So we can see that "game" is used much, much more.