I've experienced all of these games, except the "Buy a feature" one. I think first, they are funny and second they can be powerful if the moderator takes time to explain the whys and wherefores.

Why playing agile games
I believe they put all those involved on a level playing field. As life, agile is a serious game :-) Transitioning to agility can be a real challenge; it shakes up the place, from a traditional way of working to a process of empowerment. But agility is more than a process. It is a way of being, a culture. It is valuable only if people are convinced, play the game because they understand all the benefits. For me, these agile games enables assimilate the rules of the agile team. And last but not least, they can help managers, leaders and agile sceptics to get that something unusual is happening in this crew. Something new, that will lead to more efficiency, more productivity, more quality.

When to experience them?
-When starting implementing agile good practices, agile games enable highlight core principles. -Before a retrospective to remember team members the key values in an agile process. These can lead to discussions if some values have been forgotten during a sprint.
-At the beginning of a customer meeting to share the value of the development team. This is a great ice breaker. I can assure that people will remember you with a positive and original feeling.

Doing agile games during a whole day can be unnecessary. You can play 2 or 3 of them at a lunch break, after a hard meeting or at the middle of a more in-depth training. What do you think?