Absolutely. Any random level you find in the game can be saved and shared online (sharing is implemented on the PC version already, and we're looking at ways to make this work for consoles as well).
There's also a sweet freeplay mode, where you can tell the AI exactly what you want in a level: the fireball difficulty level, how hard the jumps are, how long, how fast, etc. You can save any of these levels as well, to challenge your friends or the community!
You bet! Everything in the game, from the campaign to all our mini-games, will have a global online leaderboard. Skill and competition is the heart of what this game is about.
We're also planning on weekly or bi-monthly challenges. A challenge may be a new collection of levels never before seen, or may center around a new hero type, or something more inane. All challenges will have a global leaderboard, and ranking on the challenge will earn you phat lewt.
We want the main game to be as full and awesome as possible, so we aren't just stripping out content to hold back for the Coder's Edition. Instead, once we've shipped the game we plan on taking a month or two to sit back, relax, and code some fun ideas into the game, which we'll package up and send off as the Coder's edition. New heroes, new obstacles, and so on. If people really like the new content then we'll try and take the good parts and filter it into the main game somehow, maybe as a part of a weekly challenge.
At the time we created the page, we only had permission from Steam to give away copies of the game. As of now, we have received permission from Nintendo to do the same thing! (Unfortunately we are unable to edit the text in the rewards explanations to reflect our change) But fear not! You can get yourself a copy of the Wii U game by donating to anything that mentions the Steam version!
Don't see the answer to your question? Ask the project creator directly.