This is the changelog for A Koopa's Revenge version 2.0. I'm keeping it here so beta testers can tell me if I missed anything. Also any NG user can beta test.

SPOILERS!!! SPOILERS!!! SPOILERS!!!

A Koopa's Revenge Version 2.0 Change Log
Performance:

• Removed filters from fireballs and firebars.
• Eliminated rendering of many offscreen objects.
• Removed filters from the whale graphic.

Difficulty and Balance Changes:

• You can no longer die in the spiked area of the tutorial room.
• Infinite Up adds 1% to completion percentage, making a total of 107%
• Umbreltar takes more hits from projectiles before being defeated.
• Water flowers now appear in ice levels. (Because they increase traction)
• Pipemo and Bricklets have a brief delay with animation before they attack.
• Falling beams slide down slowly before falling quickly and dropping the player.
• Bees don't require you to be as high to stomp them.
• Removed some pits from the start of 1-1.
• Slight alteration to the second half of 5-3 to make platforming easier.
• Changed terrain in 4-5 so you can't skip the Yoshi puzzle by walljumping.
• Saldadro's carrot attack now comes up from the ground and has increased startup lag.
• Slowed down Saladro's turnip arm swaying so they're easier to jump on.
• The exit to the Crashed Airship is now a hole in the ground with an exit sign.
• Several parts of 4-3 were changed to be slightly easier.
• Removed ceilings/walls from in between the rooms if the Fire Mario boss.
• Fire Mario's fireballs disappear when he panics and rockets away.
• Conveyor belts in the Burgerstein boss room speed reduced from 90px/s to 30px/s. To compensate sliders can harm the player again.
• Magic shapes/fireballs in 5-3 slowed down 20%.
• The objects Burgerstein rains from the ceiling now have a tell to show where they fall, and have twice as much time between objects falling.

Movement and Powerups:

• Added P-Speed. After running for a certain length the character will raise his arms and can jump slighty higher. In addition, the standard running jump height is now achieved at a slower speed.
• Holding up -- or down while airborne --- will change the trajectory of projectile attacks.
• Vegetables and other held objects can similarly be thrown at different angles.
• Fireballs turn into bubbles filled with smoke when submerged in water. These bubbles are boyant and will float up rather than falling. Reaching the water's surfaces turns bubbles back into fireballs.
• Jumping with the Spiny Flower performs a spinning attack that can defeat enemies from all sides, as well as letting you jump on armoured enemies. (This gives the powerup more utility)
• Bones [and their skinned alternatives] move like boomerangs instead of flying in a hammer's projectile arc. They also collect coins.
• Boo Flower allows ghostly characters to throw purple fireballs that defy gravity in a wave pattern.
• Turning around on ice without jumping is much more difficult. (To make the Water Flower more useful)
• You can't change direction after jumping, and it takes longer to reach maximum speed when jumping backwards.
• Picking up vegetables and whale teeth takes 1/6 of a second rather than being instant.
• Water power allows you to slide down walls slower than normal, as well as jump off them at a higher angle.
• Swimming with water power works more like the SMB3 frog suit. Steer with the arrow keys, press jump for fast acceleration.
• Upon reachng the surface of the water the player will cling to it until you press jump to get out, or sink back down. You will no longer bob in and out of the water.
• Holding up and then jumping from the ground while underwater results in a super powered jump toward the surface.

Enemy Mechanics:

• Coins created from defeated terrestrial enemies will hop into the air with a random horizontal speed and are affected by gravity instead of floating. (Like Super Mario World)
• Coins from defeated airborne enemies have wings, and will float away if not collected soon enough.
• Enemies defeated via invincibility get knocked into the air instead of poofing.
• Sharky the Whale receives damage from projectiles.
• Greg-Eggs no longer act like vegetables when thrown. Instead they can be carried kicked around to defeat other enemies.

Menus, Options and HUD:

• Gradient backgrounds can be deactivated for smoother video capture.
• Spare Item box moved to the top centre of the screen. (To match SMW)
• Reordered the main menu to let players get to the game sooner.
• Save games can now be backed up by exporting and importing them as plain text.
• Credits on the main menu has been shrunk down to a mouse only option in the corner.
• The key assigned to the Spare Item box is displayed when the player has no powerup but the box contains a powerup.
• Variable text fields representing lives and coins have been changed to stylized graphics. Italics removed.
• Baby Mario kill count changed from numerical text field and graphic to purely graphical display.
• Removed "Difficulty Options" as they were pretty useless.
• Customised medal get popup.
• Medal graphic backgrounds changed to blue. Many redrawn.

Player Character Cosmetic Changes:

• Improved baby kicking animation for Koopa.
• Pink Koopa is now a dragon-turtle instead of just having wings on his head. His statue form is a dragon statue.
• Yellow Koopa has black eyes to distinguish him more.
• Black Koopa has a Hammer Bros' head.
• Improved Koopa's animation for entering doors.
• Goomba now features shading to give him more depth and be more in line with the other skins' quality.
• Fire Goomba is now red like some goombas in SMB3. (The old colour scheme didn't make much sense)
• Lightnng Goomba is now a light bulb.
• Boo Goomba has been redesigned.
• Goomba's machetes have been replaced by spinning tomahawks. (Because they're boomerangs now) The machete is strapped to his back.
• Double hit Goomba is made of chocolate, with appropriate shield.
• Hammer Goomba is a Darth Vader helmet that throws lightmallets. Goomball form is the Death Star.
• Several of Shy Guy's forms have differently coloured shoes.
• Fire Shy Guy has been updated to better resemble a Flame Guy from Yoshi's Island.
• Meta Knight Shy Guy now flies using his wings rather than a cape to fly. Includes a new running animation.
• Shy Guy's Phanto mask has a red side and a beige side. (Like in SMB2)
• Shy Guy's chainsaws have been replaced by spinning buzzsaw blades. (Because they're boomerangs now)
• Water Shy Guy now wears a cuba mask (over his regular mask) and has a scuba tank on his back.
• New swimming animation for Water Shy Guy.
• Holding up will cause Koopa and Goomba to look upward in most animations.
• Increased size of Spiny Egg roll attack to match new abilities.
• Removed Boo Ball roll sprite because it served no purpose.
• When turning around at high speeds the player character kicks up dust clouds.
• Added animation for plucking vegetables and other whale teeth.
• Map sprites updated to match in game appearances.

Enemy Cosmetic Changes:

• Spiny Shrooms have a new walk cycle.
• New outlined poof cloud death.
• Unique cloud for enemies felled by lightning bolts.
• Most enemies explode on impact with fireballs instead of turning into piles of ash.
• Dirt Diggers have open their eyes to look aroundbefore the player gets too close.
• A flurry of dirt clods is released when Dirt Diggers jump out of the ground, and when they are defeated.
• Drill pillars from the pyramid have been altered to add depth and animate when moving.
• Firebars become spiked balls under water.

Boss Cosmetic Changes:

• Dan's gadokens have a new animation.
• Dan has been given a victory pose.
• If you fight Dan, Zangief will replace Monstario as the final boss's second form.
• Umbreltar doesn't turn completely red or white during his laser attack. Filters removed from laser itself.
• New mushroom themed skins for Popmo, Saladro, Umbreltar, and Burgerstein.
• Redrew most of Saladro. Turnip arms are anchored lower and further apart.
• Redrew Fire Mario so he loks more on-model.
• Fire Mario doesn't rocket away after 4th defeat.
• Redrew and or added detail to parts of Burgerstein.
• Doubled the number of inbetweens in most of FSM's tentacles.

Environmental Cosmetic Changes:

• The player and most enemies appear in front of quicksand.
• Barber pole stage exits are now yellow and green if previously cleared.
• Dirt Diggers' holes are rounded instead of blocky.
• ! Blocks and Switches were redrawn to appear shinier.
• Redrew palm trees in 2-2 and 2-A.
• Desert pillars resemble pipes instead of using a gradient texture. This puts them more in line with the rest of the game.
• Mario statues have added shading.
• Tufts of grass and bunches of flowers dry up when hit by fireballs instead of turning to ash. They can be shredded by boomerang attacks.
• Added more detail and animation to conveyor belts.
• Vegetables no longer rotate before they hit an enemy. Vegetables appearance slightly changed.

Miscellaneous:

• Pink Power Petal replaced by Dragon's Eye Scale. Effects are the same.
• Pink switch room replaced with themed outdoor dragon shrines.
• Added 30 new flower faces for a total of 41.
• Added 4 new medals.

Bug Fixes:

• Pausing will hault the movement (and noise) from spiral pillars.
• Bloodshed cheat now maintains status as unlocked when saving with it turned off.
• Fireballs now bounce off slopes instead of passing through them.
• Rolling logs can be stepped on as soon as they are visible.
• Sharky the Whale returns from death after ten seconds pass instead of when the point where he was killed leaves the screen.
• Collecting a powerup and using the reserve item at the same time no longer deletes and item.
• Hint Boos option now saves properly.
• Getting hurt while charging a spindash will now cancel the spindash
• Saladro's wind attack no longer pins the player to the wall. You can run to escape it instead of needing to walljump.
• Thwomp-stomping hurts the Flying Spaghetti Monster instead of bouncing on him.
• Holding sideways to fall off a ladder no longer works if you're climbing up or down.
• Dry Bones is immune to Umbreltar's acid rain, like all other acid.
• Player cannot turn around while in baby-kicking animation.
• The jump button must be pressed after ducking to initiate a spindash.
• Fire Mario no longer hamrs the player while rocketing away.