I like run approach to scripts management.
I find it clever, and I think it can be much more understandable in a lot of situations.
However, what I would miss is something similar to prerequisities.
Since run does not "produce files", but instead "runs scripts", I would assume this would be a list of commands to be run before the choosen one.

For example:

hello-world: get-name
    echo "Hello, ${NAME}"

get-name:
    read _NAME
    export NAME=${_NAME}

Of course, this example makes no sense, but shows the idea.