It's looking good! I have two questions right now.
Firstly, technically, you're helping Wikidata directly, and only helping Wikipedia indirectly. What is the thought process behind saying "Help Wikipedia!" and not something more accurate?
Because Wikidata is an incredibly complicated project, one that even many Wikipedians don't really fully understand the nuances of -- good luck explaining it in a sentence or two on a small mobile screen :)
More generally, though, Wikipedia is our flagship project and the only one with broad name-brand recognition. Wikidata has many important applications, but the foremost is to provide structured data for and about Wikipedia -- so, while vague, "help[ing] Wikipedia" is in fact what you're doing by playing these games.
I find it a little frustrating to not know how it is that I've helped Wikipedia. I thought "Sure, I'll help Wikipedia! No, he didn't go the Pratt Institute. Oh, well, what did I do?". It actually slightly disinclined me from wanting to do it again, because I wasn't really sure what I'm doing. On the other hand, you don't want to be overly verbose and show people too much information. Have you thought about adding a prompt to get more information for those that are curious?
Yes, we'll test a secondary screen that has a bit more explanation of how this tagging helps Wikipedia (e.g., test a few bullet points like "it will make Wikipedia information easier to use in other languages," or "it will add more context when you search," etc.). But I do want to balance instruction with ease of use; the whole point of this kind of contribution is that, unlike freeform editing, you shouldn't need to read a manual to feel comfortable doing it.
All the copy in these prototypes is still very much TBD, and we definitely haven't nailed down the UX for a live-in-production MVP. Our challenge for the rest of the quarter, through a combination of in-person testing and alpha/beta user validation, will be to find a framing that works in both tone and substance -- something that won't scare people away ("ack, it's a quiz!" or "ick, it's an ad!") and will provide them with a value proposition that makes sense -- because for a feature like this, the devil is really in the details.
These questions are kind of idealistic and not so practical, but I enjoy being able to take off my very practical product owner hat from time to time. :-)
Dan