Amending the Snake Game with Lazers design

After talking with some folks, it seems like the game design could be tweaked a little bit:

• The lazers can be used to slice your own body. The pieces of that segment will die!
• Doing so however will set you back in the purpose of the game, which is to win by filling up the entire board with your snake body (not sure what % of the gameboard it should be... maybe 70% of all the available area?
• The lazer can only be used after you get at least 3 consecutive apples or something like that.