What's the objectives for the eggs?

The eggs hatch animals that you can use to earn things. E.g. hearts, stars during tournaments, brilliance points, etc. Once you hatch an animal you can click on it to see what it will give you if you select it. The more rare ones earn you greater amounts of those things. Once you have multiple animals you can select one and use it and then swap it out for a different one anytime you want. The hearts that you collect are what you use to hatch the eggs. Some eggs require more hearts to hatch than others. 900/1500 hearts. Some animals earn you brilliance points, some give you bees to collect more coins, some give you more stars during tournaments to add to your score, some give you cocoons for the butterfly events, some give you binoculars for the portrait events. Also, each animal will collect additional hearts for you in varying amounts. Using them can be very helpful. Once you have some animals hatched, you can decide which one to select depending on what you are trying to do. You just click on the paw icon in the bottom middle of your screen and select the animal that you want to use. Once the animal is on your screen you will see a little button above it that when you click you can select to do an activity. Each one is timed.e.g. 45min-2hours. After the time is up you simply collect your prize. You don’t even have to be playing to earn the prizes. Once you start an activity, you can just go back in after the amount of time has passed and collect. You can also pay to complete an activity earlier if you want. After using an animal so many times, the animal will “go to sleep” which means you can’t use that animal again for a certain amount of time. Then you can swap it out for a different animal to continue collecting things. Hope that helps.