Given that there are zillions of lisp variants out there, why would someone want to make serious use of this compared to something like Guile Scheme (or one of the other schemes)?
Having said that, the website and branding is really pretty!!! In particular, I absolutely love your usage of color gradients. Some minor feedback is that when the screen is wide, I think that would be nice if the "A small, lisp-inspired, functional scripting language / Get Started" element flowed to the middle relative vertically to the examples column rather than floating at the top. (I do like how it floats above the right column when the screen is narrow, though.)
Also, just to check, do you have a time limit set for the Playground so that people do not over-tax your system? (You might also look into WASM so that people run their scripts locally.)