Escape From Minecraft

Setup - Added command blocks to set difficulty to Easy or Normal in addition to Hard.

L1 - The player(s) start with a wooden sword now which they did not before.
L1 - upper spawners need to be flush with wall to not suffocate the mobs they spawn.

L2 - Reduced the number of chasing blazes from 8 to 6.
L2 - Added decorative nether wart as well as some nether wart loot.

L3 - Increased the wait time until slimes drop down at the very beginning of the level to 3-4 seconds.
L3 - Fixed the incessant, clocked dropper ticking for the L2 blaze spawners.
L3 - Hid a sign explaining that the ores in the Abandoned Mine level 04 mark the path (Coal -> Dead End, Redstone -> Danger, Gold -> Chest, Iron -> Escape Route).

L4 - In the pre-level/safe-house, added 1 coal block on a dead end and 1 gold ore towards a chest; the other ores were already in place.
L4 - The early cave spider chest has been fixed so the spiders no longer always instantly suffocate when they spawn.
L4 - After 1st minecart use (the one with the jump), added gold ore to indicate the goodies down in the abandoned mine.
L4 - Improved the issue where using the 2nd minecart did not trigger the correct spider spawners; the spiders sometimes still suffocate instantly when they spawn.
L4 - Near the end, fixed being able to escape the easy way and go backwards to collect a treasure chest; now you have to jump up for it.

L5 - Added 4 melon slices to a chest in the pre-level for use later on in making glistering melon, if the player wants to.
L5 - Removed the 1 excess emerald from the last pair of chests -- in the treasure room after the throne room.
L5 - Moved the "Escaped!" sign over one so the upwards heat from the lava trap would not ignite and burn down the sign.
L5 - Added the "Pin-proof Cushion" (iron chestplate w/ Projectile Protection IV) to the garden treasure chest.

L6 - Added 10 gold nuggets to the previous 8 gold nuggets in the hidden "house" room so the player can make 2 gold ingots to repair their items with, or they can be used to make glistering melon(s).
L6 - Added a hidden hint about the nighttime relief from the jumping challenge.
L6 - Added an an emergency exit from the hidden "house" room in case you respawned there after altering the logic puzzle to close the room back off again.
L6 - Decreased the maximum number of skeleton archers that can spawn at very end of the level from 16 to 8.
L6 - Added the "Full Keval Jacket" (leather tunic w/ Blast Protection IV, Unbreaking III) to the right-hallway treasure chest in the logic puzzle.

L7 - Added a missing potion brewing stand to the witch's hut.
L7 - Added the "Long Fall Boots" (leather boots w/ Feather Fall IV, Unbreaking III) to the chest under the swamp after the witch's hut.

L8 - Added one additional Jungle Leaves block to a tree near the end because it was impossible to move clockwise around the tree.

TOP - Added glass and lapis blocks to the roof to prevent an unlucky lightning strike from burning away flammable blocks.

Finale - Added a sign displaying the total count of possible emeralds for player to compare their collection/score against:
---> {L1 = 5e, L2 = 7e, L3 = 8e, L4 = 9e, L5 = 7e, L6 = 9e, L7 = 10e, L8 = 12e, L9 = 20e} total = 87 emeralds

Caveats

Finale - It is still the case that the ignited TNT in the finale spectacle has a chance of falling on the sky island pressure plates, teleporting you back into the destruction.