Mining Rush 3D: Idle Merge is a free game available on the iPhone platform developed by TapNation. The game is set in a deep underground mine where you start by hiring miners and making your first profits. As you progress, you can upgrade your characters by merging them together to earn more and dig faster. However, you must be careful as legends say there are monsters lurking in the depths of the mine.

The game's graphics are impressive and give a realistic feel to the mining experience. The controls are easy to use, and the gameplay is addictive. The game also features a variety of characters and upgrades, which keeps the game interesting and challenging. Overall, Mining Rush 3D: Idle Merge is an entertaining and engaging game that is worth trying out.