just submitted s3put package for review but you can still install it by
choco install s3put --version 2.1.1

"s3put is a really quick'n'dirty CLI app for [S3] and [GCS].

Originally, it has been written during an S3 upload which was taking too long, because there are no tools which support multiple parallel uploads. s3put does. Later, the capability for getting buckets and copying them to the local disk was added."

https://github.com/surma/s3put