Both movies came out around the same time and I think they have a fair amount in common. Both movies have a fair amount of the "Can they do it?" tension and detail the events behind a major trend.
I think I preferred BlackBerry over Tetris. It seemed more grounded in a way where as I felt Tetris depicted Tetris, the game, as bigger than the second coming of Jesus and sliced bread combined. I felt like it made for a more enjoyable and relatable story.
For a Canadian film it has a surprising amount of big names such as Glenn Howerton (Dennis from It's Always Sunny in Philadelphia) and Jay Baruchel (from Tropic Thunder and Knocked Up). Here is a Wired review and here is the IMDb page if you are interested.
This recommendation also works in reverse because I haven't seen Tetris but really enjoyed BlackBerry
I would agree with that. I feel like Tetris is a bit more of a wacky family movie than a documentary but still enjoyable