Hey Tania, thanks for your feedback! It would be great to see what other motivation techniques people share.
I remember Kitchen Master really well, it's so engaging and looks so inviting. I really like your idea of giving the learner the opportunity to receive a particular 'level' of badge or prize... I can hear a cheesy presenter voice going "and now.... in the green corner.... playing for a gold badge...."
I also think that the language one uses can help motivate learners. It sounds like a small thing that will have no impact, but at least for me it really does, it makes the experience much more engaging. For example, in your Kitchen Master, you ask "are you ready to become the ultimate kitchen master" rather than starting the course with something like "Click the button to learn how to cook" or similar... the language you chose just makes me want to keep going (and I really do want to become a Kitchen Master!)