A very good looking animation!

I feel like the timing should be adjusted in places,
like there should be at least another second between the keyframes of the start of the tongue, and the tip of the head.
The swallow seems just a little too instant from it, for how long the face is pointing up, especially.

In fact it seems you're compensating on the lack of timing by speeding up the framerate and you shouldn't do that.
You should focus on timing your keyframes in, at least 25fps first
and then fill up the inbetweens so it can look even smoother in higher frame rates.

For a more expensive animation commission these would all be considerations, but this was an experiment in limited animation for a less-than-24-hour turnaround, as a budget animation commission option. One of the elements of the limits was a time-cap, so I don't spend endless time as the animator tooling around with timing and inbetweens, things that might make it not worth the time. As such to come in under the time cap, and because Aesprite the program this was animated in doesn't do traditional FPS timings, I played with the FPS for certain parts of the sequence to keep it simple and fast. Most of my animations don't do that.

AAA RIGHT! I've actually started using Asperite myself, and you would be right,
it's anything but typical for what you would do for other forms of media.
Shoot if anything, you're a little more experienced at this program than I am. haha