Game crashes! HELP

Hello.
I made a new grass system which is based on animation instead of Physics to improve the speed of the game.
BUT it now starts crashing if im trying to moe the lawn :3
Please help!
The blend is downloadable below:3
( it crashes when trying to cut down the big grass field . Just hit it a couple of times and u will see ;D )
Link: https://www.dropbox.com/s/ghcgytlihbe3hi6/The%20Legend%20of%20The%20two%20Brothers.blend1?dl=0

OK, so here’s what’s up.

  1. Please isolate the problems in your example blend files. Nobody wants to download a huge file to troubleshoot a 2 minute problem. (Your file isn’t that large, but if you can distill the issue into as small a blend file as possible, it helps.)

  2. On trying it, I didn’t get a crash, even after chopping down all of the grass twice. What version of Blender are you using, and what kind of computer do you have?

Well im using 1.71 . I should prob download the new one D.
Im having a notebook with ati graphics and an intel core i3. 6 gb ram