I agree with Noel about PLAI. It might be an excellent follow-up. You could also look into the Racket Guide for transitioning to Racket. If you want to keep w

I agree with Noel about PLAI. It might be an excellent follow-up. You could also look into the Racket Guide for transitioning to Racket. If you want to keep working on more complex interactive programs, instead, the lux module (https://docs.racket-lang.org/lux/index.html https://docs.racket-lang.org/lux/index.html) might be more efficient than 2htdp/universe. The latter is just amazing, but not intended to be used in contexts where performance may matter, at least in its current implementation.