Does it get overly hot when you're playing? Computers shut down to protect components when a part is overheating. Also, check the minimum requirements for the game to see if your Dad's laptop is good enough to play. If it is not, or is only just good enough, the components will be working very hard to give the same performance as a higher end laptop, causing it to get rather hot.
If it takes a while to shut down during the game, you should check the temperature of components using some software. I personally use hwmonitor.
Though if you respond as it being not very hot then i'll post another answer