Implement mechanism for creating declarative animations.
Keep in mind further implementing of animation editor.
Implementation notes
Animation is component, that can be dinamically added to game object.
Keyframe-based animation uses {local time -> attribute value} mapping and interpolation to calculate values between known time borders.
Game objects has better jobs than managing thier list of animation. I suppose AnimationManager can do the things. Game object now can have field with animation manager, and can add one's update to it's update function.
Abstract
Implement mechanism for creating declarative animations. Keep in mind further implementing of animation editor.
Implementation notes