What are some alternatives?
When comparing Retrowave Illustration Pack and Freebbble, you can also consider the following products
Stubborn Illustrations - 30 little exciting stories from the startup world
Interfacer - Collection of more than 200+ free design resources
Stories by Freepik - Awesome illustrations for your next project
Freebiesjedi - Discover & download useful freebies everyday
Illustration Tools - Directory of tools and resources for illustrators
DesignBase - Visual inspiration bookmark tool within your Dropbox