4 stars: Nice game and time killer. Not too hard to get free Gems, nice addition. Excellent work. Only problem is occasionally game will force close in the middle of digging. I reload to find my energy or Gems are taken, but not know or see what the rewards is/are. Fix this by in-game recent rewards list notifications or game disconnect detection and refund of energy or Gems. Overall great job.
3 stars: Way too RNG based. Don't get me wrong, the gameplay and concept are great... But everything, from the gear, to the cards to the artefacts, are all based on luck, with 90% of them being garbage (pet cards, coal cards, cosmetic gear etc.). The 10% you need to get high scores in the game, you have to grind for and you are still limited by the time spent waiting for energy refill or factory production, meaning gem spending is the only way out :(
5 stars: Loved the first game and this one is even better in almost every way. As someone who is over level 118 and prestige 6 I think I can say for certain this game is amazing. The game is a lot less fun without gems (I've never spent money on any) but I've got 1,000+ gems for free using tapjoy which makes the game even more fun.
5 stars: It's a very fun game. It kills time and entertains me before bed. Customer service is also prompt with returning messages and fixing issues that arise. Keep up the good work guys!
3 stars: Not very Fun, I have Played Games Better. I'm looking For Some Thing Different. The Game Is ...