You must score a minimum number of points if indicated as such in your ''Total Score'' to unlock the indicated Situation(s), which has 10 Stages each.

Situation 08 - Total Score at least 4200 points.
Situation 09 - Total Score at least 5600 points.
Situation 10 - Total Score at least 7200 points.
Situations 02 through 07 - Complete all 10 Stages of Situation 01