Hi Hilco, you can use the --start-at-task option to start execution of a playbook at a given task. The --step option can also be used, which asks if you wish to skip each task in the playbook (you can give it an answer to stop prompting and just run as well).
I am just now noticing that there doesn't appear to be any documentation regarding these options on our docs site, so I'll create a github issue for that as well.
Finally, when a task fails, a "retry" file is created, which you can use to re-execute on hosts which have failed.
Thanks!