Yarn untangling game, seems like a variant of Unpacking/Nut & Bolt.

Yarn untangling game, seems like a variant of Unpacking/Nut & Bolt. There's a 15-minute timed mission, and watching ads gives rewards. There are hidden missions: Initially, promoting to any rank gives 1000 gems. Reaching level 5 gives a reward, likely 1000 gems. Reaching level 25 gives 14500 gems. Reaching level 50 gives 14500. Each stage only has two slots for yarn, and extra slots can be unlocked by watching ads. Watch ads when you're stuck.