Precisely. Design should focus on the learner - what the learner needs to do to prepare for learning, connect with the new skill/knowledge, practice with it, and apply it.
(Point being -- if this game is a review for trainers you are training, why even have lecture as an option in the first place? Food for thought.)
Using humor; real case examples; instructor moving around the room; taking frequent breaks; having participant handouts so that note-taking isn't necessary; comfortable environment (seating, air temperature, sound/noise levels, lighting, etc.); and instructor who is passionate about the subject.