The release of Version 3.0 included a large number of new features and enhancements, as well as a large number of bug fixes in the editor, rendering, iOS-related, physics, scripting, and networking.

The major features of Unity 3.0 included:

• Support for Android OS
• Improved standard asset packages
• Improved editor
• New graphics features
• Asset pipeline improvements
• Audio improvements
• Physics improvements
• Documentation for scripting features

Version 3.5 represented a tremendous update and was released in 2011. It included support for Flash deployment. Additional key updates included:

• Shuriken particle system
• Built-in pathfinding
• Upgraded occlusion culling
• New level of detail 
• Linear space lighting