The key thing to making motion look exciting is to
avoid linear timing. By that, I mean avoid having each frame (=moment in time) be the same amount of physical movement away from its neighbouring frames, like you have in your sprite. Instead, have speed-ups and slow-downs, and have things overshoot their motion, and have segments lag behind.
In Pixelnick's example, the chest starts opening slowly, then greatly speeds up, and then it bounces a little as it comes to a stop, this feels very springy and happy. If it had bounced at the start, it would've given a different look, one of hesitation, or of difficulty opening.
Look into animation timing. It might seem like a very general and basic thing, but that seems to be your struggle currently. Learn about timing and I'm sure you'll have an easier time figuring out how to make your chest animations great, along with all your other animations.
Here's a very basic illustration to get you started. All of the animations have the same number of frames and the frame rate is constant, but the timing of the motion is different.