Proto:The Bugs Bunny Birthday Blowout/Stage 1

Graphical Differences
The first of the graphical differences. The dirt was given more detail in the final version, in the form of wavy lines.

While the tunnels Bugs uses are grassy hills in the final version, they're flower pots in the prototype!

The above design alteration called for a change in what came out of the tunnels. In the prototype flowers come out of the flower pots, while in the final version it's some kind of rock.

Come to think of it, the notion of a flower harming Bugs may have been ridiculous enough to prompt an art change.

The waterfall art was changed for the final version, for better or worse.

These spikes are animated incorrectly in the prototype. They seem to be going into the ground rather than protruding out. There's also some odd shading around the spikes that was removed in the final version.

Level 1-1
Level 1-1 is the only stage in the prototype with (preliminary) enemy placement. Significant differences in enemy placements include the Bomb/Alarm Clock enemies, which aren't encountered until Level 1-2 in the final version. The final also adds a Walking Mallet to the start of the stage, and moves the Hawk further to the right. The Grey Soap Box was changed to a red box, and an additional Walking Mallet and Soap Box were added to the end of this section.

The misplaced tiles are a product of the bad dump. This only seems to occur in Stage 1. The lone rock by the second to last carrot was removed before the game was finalized.

The (mostly useless) floating platform was removed entirely from the final version. The single Red Soap Box was replaced with a Walking Mallet and Hawk. In the spike section, the Hawk was moved to the right, with a Soap Box above, and another Walking Mallet was placed in the middle. Again, the Grey Soap Box was replaced with a red one. The Walking Mallet above was moved to the rocky hall below, and the bomb enemy was removed entirely. And, at the end, two more Walking Mallets and a Soap Box appear in the final version.

The final version adds a speed-up power-up at the start of the section, and changes the four rocks surrounding the lone carrot into additional carrots. Note that the tiles making up the hills and cliffs are using the same design as the diagonally striped rock platforms at this point. Those tiles do not yet exist in the prototype.

The two boulders at the start of the section were removed, replaced with a Red Soap Box and a Walking Mallet. The first Bead Snake's slot was taken over by a Walking Mallet, the Red Soap Box was moved to the left, and the last boulder was deleted. A final Walking Mallet is found where the Bead Snake and Hawk used to be.

The fragile rocks are marked with a different palette in the prototype. The two breakable rocks in front of the first 3 carrots were removed, the speed-up icon was replaced with a heart, and the rocky platform above the see-saw was connected to look more aesthetically pleasing.

And this is where the enemy placement stops. All of the boss rooms in the prototype are devoid of objects, which makes it impossible to actually complete anything. The final version adds Daffy Duck, a "Rabbit Season" sign, and a large carrot. To make room for these objects, one of the carrot icons was removed.

Level 1-2
Though there's a complete lack of enemy objects from this point, miscellaneous objects like floating platforms are properly placed. Two test objects are present in the prototype: A waterfall from Level 4, and a Big Carrot. While touching the big carrot will send Bugs into the end level sequence, the end level music will never stop playing, effectively freezing the game (you can "fix" this by setting RAM address to  when the end level music starts, though all it does is send you straight to the next level). The first floating platform was removed from the final version, and two more carrots were added above the second.

The floating platform to the right of the first was removed in the final version. The carrot above said platform was removed, and two more carrots were added to the rocky platform below. The carrot group at the top of the level was changed from 3 to 4 carrots, and the two breakable rocks were removed. The prototype has a number of rocky platforms in the middle of the first waterfall that were removed from the final version, though the final does have one rocky platform at the bottom, and a floating platform added where the rocks used to be. More added carrots in the final: There are six carrots by the see-saw rather than three. The three rock platforms above those carrots were removed. To the right of the third flower pot is a group of three carrots in the final, while the prototype has a speed-up icon, a carrot, and a rock. The carrot furthest to the right is a heart power-up in the final, and two rocky platforms were added below the floating platform.

Tweety doesn't show up in the prototype, and his room has more grass. The strangely positioned Walking Mallet and floating platform were removed from the second room. The speed-up icon was moved down and to the right, with a carrot taking its place.

Level 1-3
Elmer Fudd is placed right at the start in the prototype version for testing purposes. The floating platforms were moved more to the right. Nine(!) carrots were added to the right of those platforms, which are now blocked off by breakable rocks. The second-to-last carrot was moved to match the height of the last carrot.

The two breakable rocks around the speed-up icon are gone in the final version. The penultimate set of carrots line up in the final version, and the last set moved up a bit.

The hammer power-up was taken out, replaced with a carrot, and the speed-up icon replaced with a heart. A random assortment of fragile rock platforms appear in the prototype. These were removed and replaced with six carrots. With the addition of those carrots, the last two carrots in the prototype are not present in the final.

Hey, carrot placement differences! There are six carrots in a curved path, while the final has four carrots in a straight line. Apart from the other missing objects, the second floating platform was taken out of the final release.

Level 1-4
Only one difference in this section: An additional disappearing platform is placed to the right of the second tunnel.

Plenty of changes there, though! More lining up of carrot groups / rock platforms can be seen at the top-left corner. Two more disappearing platforms are in the prototype: These were removed, and the three carrots above those platforms were moved below. The last diagonally striped rock platforms was changed to a group of 3 carrots. The carrot arrangement at the end was changed to cluster the carrots closer together. There's now two groups of 4 carrots at the bottom. The two rocky platforms at the center of the first waterfall were removed, and one rocky platform was added below the last floating platform.

The boss room is identical to the one in the final version, barring the appearance of Wile E. Coyote. In the final version, it's no longer possible to go across the second room, eliminating a shortcut present in the prototype. The hammer power-up was changed to a heart, and the speed-up icon changed to a hammer. The third room has no changes other than the improperly placed disappearing platform.