The time remaining warning inside assessments is very nice, but there should be a more obvious warning for students before they begin a timed assessment. For some students, the counting down timer may be their first notice.
If possible, there should be a note on the Assessment list page (see assessment-list.png).
The note on the Begin Assessment page is there, but not obvious. At a minimum, I believe the "Time Limit" line should be in bold red text. I would prefer to see text just above the button that says "This is a Timed Assessment. You have X minutes to complete this assessment." and the button to say "Begin Timed Assessment."