So I was playing on my Android device in the Momir event and won via my opponent drawing from an empty library but didn't receive the achievement. My opponent had gotten out a token of Territorial Bruntar and Bonny Pall, Clearcutter. They placed a land triggering Bruntar which then exiled their whole library due to the nature of the event and then proceeded to attack triggering Bonny Pall leading to them losing via an empty library on their combat step. It was honestly hilarious but then I thought about the "Mill-icious" achievement and was saddened to see that I still didn't have it unlocked even after restarting the game. Would love if this was fixed and my achievement doled out!