It is a P2P file sharing system. If you’re torrenting the client you need a torrent client, (I would reccomend Tixati), then click a magnet link on the downloads page and open it in Tixati, or download the torrent file and then open it in Tixati. Also, if you were trying to do a normal download via Chrome try another browser, such as Firefox, as Chrome seems to corrupt large files very often. Also, the Blast Client is uploaded to MEGA, so you could download MEGA and download the Blast Client through it.