Different Weapons and First Aids
While you're in the game and you have blown the CRAP out of each other and you're low on health or ya need a different weapon, just push [Alt]+[Tab] and it will miniimize it. Now if you want you can pusn [Alt]+[Tab] again or you can use the mouse and click on the minimized game on the tool bar on the bottom of your desktop, now all you have to do is keep doing that over, and over and soon enough you will start getting different weapons and also first aids.