If I had to choose just one 2D tool from the Asset Store, it would definitely be 2D Toolkit by Unikron. It offers a simple and efficient way to render 2D graphics – sprites, tiles and animations in Unity.
It’s very easy to get started with the toolkit and offers good documentation on their site and the API is clear. It takes out most of the pain points in Unity’s lack of native 2D development support. It’s easily worth the price.
Some feature highlights I’ve noticed so far:
- Good frame-by-frame animation support. You can define a independent FPS for each animation or even individual frames
- Tiled sprites, and tilemaps for old-school tile-based games
- Texture atlases built in and easy to manage – reduces draw calls and makes your game run faster
- Renders pixel-perfect and no need to mess with mipmaps etc.
- Great in-editor tools
- Easy to draw your own polygon colliders on top of the sprites in the editor
The only minus point is that Unity 4.3 seems to come with a lot of these features built-in so it is unclear how useful 2d toolkit will be when it launches. In the meantime if you want to get 2D games done, it’s definitely the way to go.