I just finished all of the challenges and wish there were more
It gets 75% (assuming even one and two drop count and no zero mana drops in your list) of the cascade while Bloodbraid is 67% (again assuming even numbers of one, two and three drops)
Equally important is respectful use of notifications: deliver timely alerts about bonuses or tournament starts, but let players customize frequency and category so messages remain welcome
Its got a wealth of mechanics, complexity, and innovation, though theres a risk of too much stuff
Steve had another great tip for players regarding costs, saying that players should make sure the deck has cards of varying costs
The more colors youre playing, the truer this becomes, with 4- and 5-color decks heavily relying on fetch lands and mana-fixing tutors to set up their mana