This looks really well done! I was able to create a simple animation easily even though I don't know anything about animation software.

By the way, your "Features" page is really well made. I would showcase those features on the homepage. I didn't find the list of features until I clicked the link in one of your comments on HN.

You can also make your project more appealing on the homepage by including a looping demo animation (to see what's possible) and a screenshot of the tool.

Best of luck with the project!