I agree with what Trecar said. Voting or not, just make sure it doesn't become a popularity contest.
Showcasing pre-built creations sounds to me like the best way to go, so you're not limited to how fast you can place blocks. It's not supposed to be a memorization contest either.
I also think there should be more options on what to build than just CPU. If someone showed up with playable chess and fully working game logic, that sure as hell would pass too.
Maybe create a list of categories of what's allowed.
Showcasing pre-built creations sounds to me like the best way to go, so you're not limited to how fast you can place blocks. It's not supposed to be a memorization contest either.
I also think there should be more options on what to build than just CPU. If someone showed up with playable chess and fully working game logic, that sure as hell would pass too.
Maybe create a list of categories of what's allowed.