Color Hoop Stack

Game Description
Sort hoops by color. There aee 100 puzzles to solve, each one harder than the last.
How to Play
Touch a hoop then touch a holder. Hoops will move to an empty holder or to a holder whose top hoop is the same color. Hoops will not move to a holder whose top hoop is a different color. Continue moving hoops until they are completely sorted.
Tags
puzzle, sorting
Skills
problem solving, trial and error, testing ideas