King of Thieves is a puzzle game launched by ZeptoLab. Yes, it is ZeptoLab that made high-quality casual games such as Cut the Rope, CATS, and Pudding Monsters.
The gameplay of King of Thieves is similar to Cut the Rope, but the difference is that your opponent is no longer an NPC set by the game developer, but a real player. Not only do you have to steal other players' gems, but you also have to create your own defense system to prevent other players from stealing your gems.
Overall, King of Thieves is an underrated game and it deserves to be recommended!