Create a LIVE account, and you can download the game no-matter what LIVE status you are on. You will need to buy Microsoft points which cost around $20 if you want to get the game. However, you will get 2 months of Xbox LIVE on your account.
The first account you make comes with 1 Month of Gold, then you will have a leaflet that has the next. You can make 2 more accounts just to use the LIVE out of them, but then your console will NEVER give you free LIVE again. Games like Shadowrun come with month LIVE trials, but Shadowrun is an online-only game.