Little Fighter 2

It's a very simple and yet very addictive 2D beat em' style PC game. It's 100% free to play. You can take the role of multiple characters with their own special attacks. It's the sequel to Little Fighter. With more characters, weapons, and improved game play. It has many modes in which you can play. Versus mode, championship mode, battle mode, and stage mode where you move through the levels and killing increasing numbers and difficulty of enemies. You can also play with a friend by connecting to each other by IPs. The graphics aren't superb seeing it's a 2D game but it's extremely fun to play. Either when you're bored at work or just want to kill some time.