RNG-sus is king, not skill or timing. The allocated cards are mostly commons, so when you get to the third chapter, you'll be blown out of the water by the 'npc', which has better cards and, it would seem, better luck. Of course, one could buy (yes, with real money) awesome booster packs from different sets, but shouldn't a game be completely playable without having to invest that. Lastly, the tasks given before a game get you crystals, but only if you defeat the 'npc' under grueling circumstances. Meh