Oddly enough, it seems the Keys were not removed from the levels even though they are entirely unnecessary due to the Doors opening automatically on proximity. Beyond that, this level has only a few changes, with the main difference being the addition of the Nailgun/Super Nailgun with its appropriate ammo. This means this level (and possibly the Episode) is a lot like Episode 1 of the original game, all Weapons besides the Thunderbolt.
