Strawhead Samurai

http://de.bigpoint.com/mini-games/388/Strawhead-Samurai/

Strawhead samurai is a fighting game where you, as a lone samurai, have to fight an invading army. The main mechanic is slicing by painting lines with the mouse. It's a pretty cool idea and works surprisingly well. The game's a short campaign with a lot of action and some strategy at the end. It's a neat little package that should occupy you for 10 minutes or so. Give it a try.

My Brute

http://www.mybrute.com/

My Brute is a small and simple browser fighting game based on flash. Players generate a character and then fight others for experience, items and skills. They can also enter their brutes into tournaments. From my current playthroughs it seems as if players have little options beside initial quasi-random character generation but it's simpleness makes for a good timewaster.

Matrix pandemonium

http://www.maxgames.com/play/matrix-pandemonium.html

What a nice little game! You can grab almost every object in the game and throw it at your enemies. If it's some sort of weapon, you can even use it to fight those hords agents that keep coming at you. There are other Matrix characters as well, like the invisible twins. Your actions will leave marks on the environment, and to be honest I wish some games back in the days where I was playing on my megadrive would have looked so cool. Definitely worth a try!