I like the animation a lot! Nice job!

Okay, not bad... in fact, over all, I'd call this good.

It's a bit simple, but you've got something to build on. You're clearly covering the talent/skill part, so anything I might "harsh" about at this point is a matter of style vs. quality...

That said, let's touch the "simple" part. There are a few other commenters pointing out terms like "short" or asking "that's all?"...
You know how to "stack" options, since you stacked the "hand spank" with "anal beads" in the first loop... SO maybe stack two or three options with the dill... like "tease" (barely penetrate) with "slow" (what you already did) and "pump" to pick up the pace and cram them deep... or something similar.

Same could be done with the penis stage, AND as reference, I would suggest you pop into the Movies-search box and type "Mittsies" and check out some of the awesome options/stacks offered in the "Anal Rodeo" sets...

Finally, I'd suggest you give the "cum shot" a "one and done" function, bringing the viewer straight to an "end-card" of some sort... whether it's idle-screwing around... or just a list of credits (whatever floats)... AND stick a "repeat" button on there to bring the whole thing back to a start...

Options and values (being able to turn up and down volumes on sound-track/music) are great add-ons, too... BUT 1. I'm not sure how or where exactly to suggest you find that kind of technical... AND 2. The quality of sound and your editing it together is good enough I think this stands on its own merits in audio, frankly.

Don't forget to breathe, relax, and then keep on keeping on... Artists grow as they build. I believe in you. ;o)

that was pretty good, a little short. but nice to look at.

the Tumblr post gave out a different scenario. but this is still good

That was it?
No deeper penetration, no anal? Just slow movements, while barely inserting the tip?
Welp, at least the animation was good, I give you that.