"Mark Reviewed"?
 

When you review a project and click "mark reviewed", what changes in the display?

I can't tell whether a project has been reviewed or not when I look in "project" perspetive

Nothing changes unless you are grouping or sorting by review date. My recommendation is to group by review date, then march through your projects until you get to the groups that have a future review date. Each time you click the button (or press the keyboard shortcut) the current project is marked reviewed and shuffled to the appropriate spot in the list for its next review, and the selection advances to the next project to be reviewed.