'Captain America: Shield of Justice' is a free browser-based side scrolling game by Marvel which you can find online
HERE
This NES-like platform beat-em-up is actually a lot of fun with the ability to beat up your foes with either a mighty backhander or by throwing your trusty shield straight at their heads... Or you can take down a whole bunch in one go with your super-special 'kill-all' attack... Ah, I miss those old console days where almost every game was like this!
Enjoy!