You must to stack gems of same color and deposit them on deposit area (flag in minimap) before time runs out. If you are carrying yellow gems for example, you can not collide with red, blue or green gems, otherwise, the gems will clash and it is going to spread around map.
There are different obstacles in each level, such as a Totem shooting fire, the slippy ground in Ice level, monkeys that can help or hinder, all this for diversity the challenge!
You can acess Customization screen in main menu to unlock clothes and customize your character to your liking!