Needs improvment...
"Conway's Game of Life" is a great "game" and there are many good versions of it on the internet. Unfortunately, this is not one of them. After loading the movie, you meet what seems to be an empty screen, except for some buttons at the top. You should have made the grid visible from the start.
The biggest bug (or is it just me?) is that the stop button doesn't seem to work. If you had fixed this problem you would got a much better rating. I also suggest you attach a generation counter. A next button would also be nice, so that we could see how "life" envolves step for step if we want to.
Take a look at this java version: http://www.bitstorm.org/gameoflife/
You see how much better it is? Look at it, learn from it and try to improve your flash version.
The reason I give you such a low score is mainly because of the stop button doesn't work, which is really frustrating. This is a major bug. If other people, including yourself, get it working, it's still a bug, because it should work under any circumstances and it should work as the user (me) expects. That is very important when launching any kind of interactive application. The interface should be intuitive, meaning that the user don't need heavy instructions to get it to work.
My intention with this review is to be helpful and I hope you see it that way to.
I mention it again, fix the stop button.
Good luck, I know it can be hard, but given enough time and work, you'll make it! :D