This is definitely a fun game to play and you can tell Zillion Wales put in a lot of time developing it. However, if you play regularly or want to get to the higher leagues, especially diamond or pro, then you will likely have to spend money to compete with the top players who spend a lot of money to upgrade their heroes. For forging artifacts, they will also not let you choose which artifact or hero you are forging the artifact for, but they can give you a artifact you already possess. The really powerful artifacts that all of the good players have also cost around 15,000 gems per artifact (it costs $50 to obtain 12,000 gems, which would not be enough for even one of those artifacts). Furthermore, even if you buy premium, you still have to watch several 30 second ads or use gems to open chests (usually paying for premium on any site or app gets rid of ads). Passive skills is another way they try to get you to spend money, as you can only upgrade passive skills with gold and runes. They say passive skills are permanent skills that every hero uses, so I think they should be determined by how many games you have played and/or won, not by how much gold you can spend. Overall, it is a fun game to play, but you can usually tell which games you are going to lose based on your opponents’ hero and artifacts (which flash up right before the game starts).
Thank you for the review! The dev team got your feedback, and they will consider how to improve the game in future updates.