OH MY GOD I LOVE THIS. If I make a post-jam version I will add this if that's okay with you (along with any other updates I think are good).
The lava speed (technically it should be called magma but I wrote lava in the code lol) is one thing I found really hard to balance. It's definitely too nonthreatening as it is, but making it faster often made levels too difficult in the start. I tried making it speed up if it's sufficiently far away from you, but this messed up some of the levels.
Can I see the updated project file? I'm really curious lol