If you download and delete the game, all you would have to do is go back to your Download History which you can access via your account on the Xbox website and re-queue it for download at any point in time. So yes, you can download, play, delete, then re-download your games in the future. :)...
Free just until the end of the day. They are trying to get more upvotes on Steam Greenlight as well:
Upvote the game on Steam Greenlight here:
http://steamcommunity.com/sharedfiles/filedetails/?id=141030686
More info about the game and promotion here:
http://download.reprisaluniverse.com/