The little minigame that looks like an old scrolling arcade game was actually a joke? Just something to distract and break away from the code for a little bit of fun. Seems that the testers liked it so much that they demanded that it stay in the full version.
If you look in the "What Xbox games are you looking forward to" thread you will see I mentioned that as the
reason I am looking forward to it!
I saw that little game when I was watching the E3 video. It looks great! I hope they add it to the start screen so I can play it whenever I want.