Side-scrolling, 25-year-old Zelda II, reimagined as a 3D FPS... and it works!
Of course, it's not without its issues. Combat is... hairy. You can't see enemies sneaking up behind you, and they have an unnerving tendency to move quickly when you're not looking. Getting around can be a bit of a pain too -- just stick to the yellow brick road though, and you should avoid the random fights.
This reimagining is by no means complete, but there's at least 10 or 20 minutes of gameplay to sink your teeth into. If you're having trouble getting started, read the walkthrough. Also, don't forget to stock up on hearts whenever possible -- they respawn, and when you have a full life bar, your sword shoots frickin' lasers.
All in all, this is a fantastic example of what the Unity 3D engine, a dollop of belabored love and a garnish of ingenuity can achieve.
Now we just need Nintendo to release a first-party 3D version of A Link to the Past...