"We batted maturely, Luke Wright's innings was outstanding. When the guys came in at the end and struck the ball it was very powerful and exciting to see," Broad said after the match.
"In the field, we bowled well at the start, you're always going to concede a few runs in T20 but it was a good win. We are delighted at our performance.
"It's amazing to see teams like Afghanistan here, it's important to grow the game and hopefully this inspires people in their country," he added.
Asked about their dead rubber against India on Sunday, Broad said: "It is hard to say it is a dead rubber.
In T20 it is like what team turns up for the particular day and we'll be fired up and wanting a win. That's the only attitude to take when you cross the line."
Man of the Match, Wright, who became the highest individual scorer for England in World T20 surpassing Kevin Peitersen's 79, said he always wanted to prove that he was a better player.
"Yeah, it was a bit of a special evening, I was desperate to play well and win games for England so it's special to be man of the match," he said.
"We tried to hang around and see what we could get early on. As I've got older I've gone away and tried to work on my game and prove that I'm a better player.
"The amount of guys I've seen have time away from England, like Ian Bell, and come back a better players, talking to other coaches and players about how I could improve," he added. MORE