Games take long enough for updates, if you are a not that good animator put that time to develop more scenes.
But don't forget to develop the skill, so you choose
I would say : animations have my preference EXCEPT when it are bad animations vs good images -- most of the time : devs that make bad animations make bad images...
Nothing worse than cracking open a promising looking archive with a ton of pics in it only to find some jackoff decided to spam every fucking frame of some animation into it
Usually ripped from some Japanese game. Who wants to look a a hundred still frames some yahoo extracted from a fucking gif?