American football based video games are usually console games. Now there is one that you can play in your browser! Although not as cool as its 3D counterparts, 4th and Goal 2014 manages to give you a casual American football experience.
If you already know how the sport is played, the rest is fairly simple. The controls are a bit tricky and they take some time to get used to, but the game allows different modes of difficulty for beginners and a detailed controls page too. The space bar snaps the ball or uses spin tactics depending on who holds the ball. Arrow keys let you run, a, s and d keys let you pass the ball. Finally, pressing w would give you a speed boost when you need to make quick plays.