Piano Lessons: Would you rather exam or excite?

I prefer to assess student's progress regularly through games rather than to have formal tests for my music students. Although a "test" is a useful means of gauging the progress, and I use a pre and post theory test for them to earn their spot on the theory leader board, more often I prefer to use games to assess the various skills of my students in a more playful relaxing environment and achieve the same goal of discovering what they know and celebrating their accomplishments in a fun way.  Games take off some of the pressure, and in a gaming environment students are more likely to"consider failure as a tutor, not as a tragedy, and to not fear failure but to learn from it" (Lynn G, Robins, Until Seventy Times Seven). 

At piano lessons this month I'm using a quick egg hunt to start off lesson. A few eggs are hidden around the room with a challenge paper topic and treat in each one.  Students race to find an egg, complete the challenge inside, eat the treat and repeat until the first 5 minutes of lessons are up. I make the topic of the challenge pretty general and then match the activity to the current level and needs of the student.
A few sample challenges include:
Expert Ear Training- Chord Changes, Melodic Dictation
Theory Sleuth - One Minute Challenges (Scale Patterns, Notenaming, Quizlet Terms)
Sightreading Superstar or Rhythm Rocker (Piano Teaching Binder)
One Minute Club (Notes in the Fast Lane)
Minute to Win it Challenges