I think your idea of rewards for 25/…/125 newly solved exercises is great. I want to start today. Does that mean you need to call the challenge 25orMoreIn25? Or 125in25?
Please can you clarify a couple of your comments?
Do you have a link to the page with all the practice exercises? I have found, for example, Solve Beer Song on Exercism. Is that what you mean? Exercism does not work.
What do you mean by a “complete set (for all the exercises)” Do you mean for all the languages? And what do you mean by “PS”. Forgive me if this is common knowledge.