I can't tell exactly the measures on which it's being awarded aside from the generic stuff below, but it's nice to see Blackout getting some recognition. I do think the game was underappreciated.
QuoteGame Trend of 2019: Blockbusters Reimagined https://www.apple.com/newsroom/2019/12/apple-celebrates-the-best-apps-and-games-of-2019/
This year, game developers worldwide burst onto iOS with a wave of world-renowned brands, all featuring leading-edge technology, bold design and innovative features that delivered a level of depth and quality never thought possible on mobile. Hits like "Mario Kart Tour" and "Dr. Mario World" (Nintendo), "Minecraft Earth" (Mojang), "Pokémon Masters" (DeNA Co), "Assassin's Creed Rebellion" (Ubisoft), "Gears POP!" (Microsoft Corporation), "The Elder Scrolls: Blades" (Bethesda), Alien: Blackout (D3PA) and "Call of Duty: Mobile" (Activision Publishing) aren't mere remakes or tributes — they are original releases that breathed new life into the most beloved franchises in gaming history.