I do love Lost Garden's prototyping challenge, though I will never in my life prototype any game, even simple and super cute ones. However, I always love seeing what other people come up with — it's an interesting exercise in observing the design process with playable prototypes. The latest is a cute idea that takes advantage of 3D engines and real-time shade. The basic idea is that you play a farmer who has to save his haul from the scorching sun:
You play the part of a rugged mushroom rancher who must collect adorable sentient mushrooms living in the shade. All you need to do is run up to a planted mushroom and touch it. It will pop out of the ground and start following you around. Lead it back to the start location and you'll be awarded multiple point based off its size.
Unfortunately, it is a scorchingly hot day. You can meander about the landscape of giant grassy blocks with impunity due to your meglo-awesome wide brimmed hat, but the mushrooms wilt quickly in sunlight. To lead them back successfully, you'll need to keep to the shadows and plot the optimal path home.
There's a lot more in terms of what the game needs to include, and unlike a lot of previous prototyping challenges, Danc is not providing art assets, though he does make some suggestions on what sorts of options people could employ. So, if you're sitting around this month and are itching for a challenge, wander over and check it out.
Shade: A game prototyping challenge [Lost Garden]