I have to say that this game very nearly strikes the perfect balance: challenge and playability vs in-app purchase. So many others make a game entirely impossible to enjoy without effectively buying advancement. This was what killed "Order and Chaos-Online" and "Dungeon Keeper" for me – the utterly unenjoyable experienced presented when playing either without making purchases through the app. Worse, the developers never made much of an effort to remedy that imbalance.
Perhaps the team behind this game will see fit to take up "Diablo" and "Diablo 2" and do those some justice...
Certified Vampire about Prime World: Алхимия