It's a pretty good time waster. It's fun pushing the limit to see how far you can get before you prestige. Each time you prestige, you get X amount of relics. The amount of relics you earn is based off of your characters level, your group level, and the stage in the game you reach. You use the relics to buy artifacts which give you a variety of bonuses such as additional damage, or more dropped gold while playing. It's a pretty fun game, but can get boring. When it gets boring for me, I just let my characters grind for me offline, and when I open the game again, level them up, advance to a stage proportionate to my team's strength, and close the game. So either way you want to play, I think it's fun. I did buy the lowest possible amount of diamonds to get rid of the ads, so it makes the game a little more bearable. One final bit, I would not recommend spending diamonds on anything except buying things for your character, and there's no need to actually spend cash for diamonds. You get plenty of free ones in game through drops, events, ads, and weekly login awards.