You do realize Blender wasn't made to create games, right? It was developed by a swedish company for 3d Movie creation.
I have had blender for about a year and a half and I haven't gotten very far with it. Plus my Comp sucks, so. The best I can make is a photo-real apple.

ATTENTION: Anyone using this should be blessed and donate to the Free Blender Fund found at thier site.

PS: Making grass is easy. Download the Fiber python script. It is copyrighted by its creator. Found at

http://oregonstate.edu/~dennisa/Blender/Fiber2/

try it.

But if you want to make games, stick with RM2K3. Go to college get a degree in digital media and design and a degree in game programming if that is you wish. Me, I want to be a graphics designer. Play around with Blender. It is good to get an early start.