-->
Applications should help the user save time not waste it. If time is spent on an application, it should benefit the user in some form. Even game based applications should be created such that playing is fulfilling or beneficial.
Optimising an application means efficiency and usability over beauty. While creative animations and graphics can improve the user experience, a slow application will tarnish any perceived benefit.
An app that's not usable will not be used, defeating the purpose of time spent creating such an App. An App that is enjoyable to use will help retain users, increasing the App's community and profits.