One thing that I really liked about the Stars druid is that it expanded the "nature" theme of druids outside of traditional druid areas like plants, animals, elements, and weather into something new and interesting.
I know that there is a gravity wizard subclass from Matt Mercer, but I really like the idea of a druid subclass focused on gravity as well, and druids that devote themselves to master one of the most fundamental forces of nature.
To that end, this is a subclass that I put together focusing on limiting enemy mobility or moevement with a little extra damage at level 2 with a Gravity Field ability based on wildshape use. At level 6, they get a limited use ability to change damage type to essentially gravity damage (which is fun) and get a little extra damage. Level 10 gives an improved fly speed compared to the Stars druid Dragon constellation and some buffs for allies against being prone. Level 14 is an overall improvement on the Level 2 abilities and a jumping speed for allies.