Okay.
Controls;
Fire - LEFT MOUSE
Zoom Down Sight - SPACE BAR
Reload - R, or click when out of ammo
Switch Weapon - Arrow keys DOWN or UP
Tips;
In my own experience I found that using the Thompson (Starting Gun) until having the money for the BAR (2900$) was the best way to go. Being that the BAR is basically one shot one kill on infantry. Then from there going to the M19 Browning Heavy Machine Gun. (4200$)