I think the risk of "too much game" is small here.
They JUST released another bit (
http://playtonicgames.com/news.html) that really highlights why I think it'll be a success. The game at it's core is: a 3D jump-around game, with collectible items, in themed worlds which will be unlockable (separated from each other) and expandable.
I know the expandable world aspect is something they wanted to do for ages, so I think that's going to be their core for innovation. Which I think is great.
If they can deliver a collectathon with 8-10 unique worlds and a bunch of moves, I'll be happy. And I think that's exactly what they intend to do. Their new article specifies that the intent of the Kickstarter is to guarantee multi-platform simultaneous release, and fancy collectibles for your shelves at home. Not to shoe-horn in ridiculous gameplay elements.
Make the forum great again.