Is this game downloadable through steam?

No. The 4th bullet point mentions it's through Uplay. I have to imagine even if you got a steam code that it would still make you launch up uplay everytime because Ubisoft is cool like that........but the game is pretty great none the less. My Assassins Creed 4 was a steam key and it still launches through Uplay every time I play it. Be prepared for the minor nuisance.