Another way to evaluate a course (or any other activity, perhaps), that breaks from the standard evaluation form format. This one takes the form of a debate over this proposition: "This course is (has been) a complete and total waste of time and money."
Form two teams, choose sides by flip of a coin, one team is given the task of arguing for the proposition, the other against.
Give the teams 20-30 minutes to prepare. Urge the teams to be specific, to give examples, and to be truthful (i.e. not invent facts). At the same time, they need to be a bit creative to make strong arguments, especially if their own opinions are different from the position they have to argue.
When ready, the emcee announces the proposition to be debated and explains the format and rules. The "for" team speaks first, and, at the end, speaks last.
If you have large teams, you will want to do several rounds of debate, to give people more opportunity to participate. Ideally, everyone should have a try at debating. You can also form three groups and give one group the role of the audience. The audience can ask questions of the teams and, at the end, decide which side won.
Because the purpose of this debate is to evaluate the course, it is important for the Joker to take careful notes, and, at the end review them with the group.
Follow up the debate with ten minutes of writing, in which people relect on the question of the course and how it could be improved.