How do I know? Well perhaps it's because it was my son Andy jr who did it!.
We only bought the game in Sleaford on Friday afternoon after he finished school and he didn't start playing it until almost 5pm. He finished playing his first instalment before 8pm and didn't start again until 9am on Saturday morning. He had a few breaks watching TV,riding his bike and helping me do some washing (even top class cyber warriors have to do their chores!) and he eventually completed the game and got to see the end credits by 2:55pm!.
Don't get the wrong idea. Mini me doesn't spend this much time on his XBox 360 normally, but as he absolutely loves everything involving Halo, and as he had been waiting for quite some time for the game to be available, I decided to let him have a little more time on his console.To be honest though even I was surprised when he finished it in such a prompt manner!.
I have a suspicion that my son may one day end up testing games for a living, so if you are reading this post and could be on the look out for a new video game tester for your company in the next..oh....ten years or so, drop me a line and I will give him your details for future reference.
And Bungie (the game developers),hurry up with the next one will you :-)