What do you have if you remove the multiplayer component of Halo 3: ODST? A tempting $14.99 Xbox Live Marketplace download.
Microsoft has repackaged its 2009 Xbox 360 shooter, stripping out its MP components (Halo 4 is available to cater for that) and leaving it as a single standalone adventure.
It's currently available on the US arm of Xbox Live Marketplace for $14.99. It's a 3.5GB download.