In other gacha, 4* are guaranteed on every 10 roll. In here it's on every other roll. Also it seems there's no soft pity for 5*s and you have to go all the way to 80 rolls. In other gacha soft pity makes it very likely you get the 5* roll in 70~ rolls.

Very interesting decisions. I wonder how generous the free gem currency is. If it's stingy like some Jap gacha, I don't see it surviving long.