If I recall correctly, each line is either a feature to add, or a bug to fix. * means it was done on that day. + means it was done on a later day. Empty means either not done or not marked as done.
(Tasks may appear in multiple days, and there's no guarantee of tasks being retrospectively marked as complete.)
https://github.com/ESWAT/john-carmack-plan-archive/tree/mast...