The only reason you need the Bootcamp installer from the OS X DVD is to install drivers for the trackpad (multi-touch features), camera and other Mac specific hardware. The function buttons for Volume/Brightness etc. are also installed with it.
You can however install drivers for the non-Apple hardware, which is the main components you'll need for your game. The only problem is trying to determine exactly what you need. Which Mac are you using?
Typically the only drivers you'll need for games are video and sound. You only need to install one for video and one for sound only - not all of them.
My Macbook Pro has an nVidia video card, meaning the drivers here will work
http://www.nvidia.com/Download/index.aspx?lang=en-us
Choose the correct operating system - Window 7, need to determine 32/64bit. Any nVidia based Mac can use these drivers.
Some Macs have an intel video card (not to be confused with the intel architecture). Drivers can be found from the intel website here
http://www.intel.com/p/en_US/support?iid=hdr+support
Use the chooser at the bottom. You'll need the intel graphics media accelerator drivers.
If your Mac has an Ati video card, you may be able to find drivers from the Ati website here
http://support.amd.com/us/gpudownload/Pages/index.aspx
(not all Ati drivers are published - if yours is not here, you will need the OS X DVD)
I have no idea what other Macs are using for sound, however I know mine is a Realtek chipset. Drivers can be found here
http://www.realtek.com.tw/downloads...=24&Level=4&Conn=3&DownTypeID=3&GetDown=false
Installing these drivers will not break Bootcamp in any way. It is quite safe to install the Bootcamp drivers on top of these drivers (although the Bootcamp ones will be older). If you need a hand with your drivers, please post which Mac you have and an approximation as to when you got it.