My students started this lesson today and some completed it. Most students need a little more time wo get through the last puzzle. In addition I think the journaling is powerful for the students and the will need enough time to write thoughtful reflections. This lesson will wind up taking 1.5 days.
One thing I noticed: In the lesson plan it mentions that students will be practicing the action in levels 2&3. However, level 2 is the demonstration puzzle that serves as the discussion prompt prior to levels 3 & 4 which are the levels for students to implement their solutions.
Other than that one small problem, the students seemed to respond well to the lesson. The group discussion was useful and helped to reinforce the idea that there are many solutions to any programming problem. If I uncover anything else noteworthy, I'll add to this post.