Up front I'm going to admit that this demo won't have the story or choice stuff I like to talk about. That said, the demo will be fun and it will showcase the interesting gameplay that Icarus has to offer.
Since the theme of Icarus is power and the choices it creates, I've experimented with giving the player "second-hand" power. You don't actually do damage to enemies directly but instead have Garett who follows you around and will attack people for you. In this way you have a great deal of power, but the main character is still fundamentally weak and reliant. Like I said, it makes for some pretty interesting gameplay, so check out the early demo in the downloads section.
I'm also trying to figure out a good installer, so right now the prerequisites need to be installed manually if you need them. Just try running the game and if it doesn't work then start installing them. I'm finding that the .NET framework is the most common thing that people don't have and the most fundamental to XNA, so start with that.