Hoop Sort: Stack and Fill 3D is an iPhone game developed by Tapotap. The game challenges players to sort hoops by color and fix the mess. With a limited number of moves, players must strategically stack and fill the hoops to complete each level.

The game offers various features to enhance the gameplay experience. Players can restart a level at any time and use hints to help them solve challenging puzzles. Additionally, if a level proves to be too difficult, players have the option to skip it and move on to the next one. With over 5000 levels available, Hoop Sort: Stack and Fill 3D provides ample opportunities for players to test and improve their sorting skills.