Multiple delays need to be added up. For example if your first delay is 1s and second delay you want to be 1s, 2s will need to be placed (see code source).
Animate 1 element at a time.
Only px values can be animated at this time.
Chaining is supported (see source code).
With CSS transitions, most of this is obsolete. CSS Animation vs JS Animation
Animating relative values (see source code).