The only video I found on the page (the one I linked to in the OP) was http://videos-cdn.mozilla.net/serv/marketing/firefox4/Mobile-launch-greatday640.webm but that is obviously only about Firefox 4 for Android, no mentioning of this "Spark" thing.
I think it is just a "game" they made to get people to spread the word of Firefox for Android for them.
To celebrate Mozilla Firefox going mobile, we've created Spark, a game that lets you share Firefox with friends and help the flame of the open Web glow bright.
Not an Android or Maemo user?
No problem, try Firefox Home for iPhone (get it FREE from iTunes)
OR just help spread the word about Firefox for mobile to others.
And that is why I think that.
If I owned an Android I would download it to see what it is.