Overwatch's production is unrelated to Blizzard Entertainment.
BlizzCon is a video game convention held by Blizzard Entertainment to promote its major franchises Warcraft , StarCraft , Diablo , Heroes of the Storm and Overwatch . Overwatch (video game) . Overwatch was unveiled at BlizzCon 2014 in a fully playable state and was in a closed beta from late 2015 through early 2016 .