Some people are really good at everything. They can code, they can design, make textures, models, sounds and music, just everything you need for a game. Well, not me. I think I can write some code. Maybe I am also able to put some images together in Gimp and change the color. But that’s it. So what do you do, when you have an idea for a game, but you don’t have the people to make the game pretty? You browse the Unity AssetStore like you browse Steam or Amazon for your next games! It’s amazing what people sell in the AssetStore. In particular because the assets are not too expensive for and indie game developer and they will give your development process a real push. Just imagine how long it would take to make all the models and sprites by yourself or how much money you would need to pay designers for this stuff. Of course, sometimes you need custom assets you won’t find in the stores. But even in this case there are uploaders who will make assets for you on request for a little fee. If you need assets for your prototype or you see a style that just fits into your game, I recommend the Unity AssetStore or any asset store you can find on the web. It will make you happy. 
Thanks a lot to the Hedgehog Team who made the Toon Level Kit possible. Super Snow Fight looks amazing thanks to your assets! 
