I remember going to my local Game shop in 2000 to 2001 and remember seeing a display cabinet showing a demo of some game, I think Dreamcast but it could have been for a PS2. All I really remember is an image of long waving grass from a first person perspective / head height, or perhaps it was someone pushing through waving grass. I remember it absolutely blowing my mind but I have never come across the game that it could have been!

Any ideas?