So, before starting to critisize the rumba challenge, I want to underline that I think this contest is a good idea, and I would most likely participate to such initiatives in the future if any is made available. That being said, there is plenty of room for improvement about the challenge and the app/site that supported it.
First thing first, the app is not an app. Why having us download it when all it does is redirect us on a website ? Why did I needed to connect again everyday when using the same mobile device (oh and to choose my langage everytime too) ? Why am I logged on my profile page instead of going directly to my actions ? And why am promted everyday again to take a survey that I already filled ?
All these questions lead me to my first point (out of two) : please provide us with an app/website that is mature enough for us to use. Of course the website is working fine and the design is neat. But it has not really been thought for the end-user.
My second point would be regarding the content of the challenge. I am a little puzzled by the lack of actions for people who already do a few things for the planet. Let's say I already take the stairs, do not need to go on business trips and go to work in an ecological friendly way ... what's left for me as actions ? Not much because many actions are available on 2nd or 3rd week only. So it would have be nice to have all actions available from the start or if more actions for people already earth-friendly were offered.
And that's all for today. These are my critics but my main message would be : great job guys, keep moving !