Hey all, sorry for posting so much recently.

The differences between the PS2 and the GameCube versions of the game are largely undocumented. I’m pretty familiar with the PS2 / PSN version (both are the same from what I can see). So I’ve reviewed gameplay of the GameCube version and have noted all of the differences I could see. This is probably not an exhaustive list, but I think I covered a large amount of the changes.

I categorise the differences into three types:
- Level changes: Requires the user to play the level differently.
- Design changes: Are aesthetic only and do not affect gameplay.
- Camera changes: Alters the player's view during certain sections.

I use two videos to reference the times and places these changes are present. The PS2 video I use is from my own any%, and there is also a GameCube Let’s Play video I use too:

- PS2:
- GameCube:

I didn’t explore any of the bonus levels - just the first four zones and their boss fights.

As a final note, you may have noticed that the PSN version I reference is the PAL “Quack Attack” and the GameCube version is the NTSC “Goin’ Quackers”. I have looked at videos of the NTSC PS2 version and I’m confident in saying that the differences I list here are present because the games are made for different consoles, and not because of any PAL/NTSC difference. However, I didn’t look at any footage of the PAL GameCube version, so I may have missed something.

General:
- The GameCube version appears slightly darker in the level select area and yet brighter within the actual levels.
- Text is in a different font (more curvy on the GameCube) and obviously different buttons are displayed for the special moves depending on the console.
- Movement seems a lot more fluid on the GameCube version.
- Load times seem slightly faster on GameCube but this is untested.
- Orange and purple boxes are shaded darker on the GameCube.
- The life icon of Donald's head is a lot smaller on the GameCube.
- The lids for the level entrances are coloured differently between versions.
- The GameCube version has an extra "Continue without saving" option if you choose to save after a level is completed.
- Floating boxes only have shadows on the GameCube version.
- I'm 80% certain that the Nephews only tell you when you've collected all of the special moves in a location on the GameCube version. I'm pretty sure that this is absent entirely on PS2. [GameCube: 31:32]
- When a zone is not yet available the TV screens are black on the GameCube version, but display static on the PS2. [PS2: 19:05] [GameCube: 35:56]
- Donald's shadow is oval-shaped on the PS2, whereas his shadow is more realistically-shaped on the GameCube. Ex: [PS2: 29:05] [GameCube: 50:42]
- Backgrounds are often modeled differently in subtle ways.

Forest general:
- Design change: Some rocks appear more detailed, trees are darker, and particular logs are coloured differently. Some extra trees are visible in the background of the GameCube version. Ex: [PS2: 2:09] [GameCube: 6:29]

Forest 1:
- Level change: Near the start of the level the GameCube version has three extra gaps which require platforming to get across, whereas the PS2 version has land covering all of this area that you can simply run through. [PS2: 0:49] [GameCube: 4:44]

- Level change: Another extra gap is present on the GameCube version. Also the fence posts are designed differently. [PS2: 1:27] [GameCube: 5:34]

- Level change: There is a bigger ledge on the GameCube version immediately followed by a different ground texture. [PS2: 1:30] [GameCube: 5:38]

Forest 2:
Level change: There is a bigger ledge on the GameCube version which is filled in by horizontal logs. [PS2: 3:32] [GameCube: 9:21]

Design change: Water appears a lot more detailed on GameCube, and the more obvious current gives the impression that the area is longer than it is. [PS2: 4:11] [GameCube: 10:11]

Forest 3:
Design change: More detailed waterfall on GameCube. [PS2: 5:30] [GameCube: 12:28]

Forest 4:
Level change: An extra log and thorns appear on GameCube. [PS2: 7:33] [GameCube: 15:56]

Chicken:
No obvious differences.

Duckburg general:
Design change: Fire hydrants spit out white water on GameCube and blue water on PS2. [PS2: 10:34] [GameCube: 22:41]

Duckburg 1:
Design change: The logo and text on the moving vans is only legible on the GameCube version.

Design change: The skybox is darker on GameCube.

Duckburg 2:
Design change: The PS2 version seems to take place at evening whilst the GameCube version seems to take place at daytime. [PS2: 12:53]
[GameCube: 25:43]

Camera change: The GameCube version pans down just before the second thread area to reveal extra windows and boxes, whereas the PS2 camera remains straight throughout this section. [PS2: 13:40] [GameCube: 25:53]

Camera change: The camera is raised slightly higher towards the end on the GameCube version. [PS2: 14:05] [GameCube: 26:43]

Level change: There is an additional box on the PS2 version. The paint cans to the last thread are also bigger on GameCube (as the ledge they are next to is bigger itself) [PS2: 14:11] [GameCube: 26:52]

Design change: Additional trees are present in the background of the PS2 version. [PS2: 14:32] [GameCube: 27:22]

Duckburg 3:
Design change: Additional boxes are present during one section on GameCube. These appear to be a part of the background however and are not climbable. [PS2: 16:04] [GameCube: 30:13]

Design change: A two-lane road (in the background) on the PS2 version is changed to a one-lane road with additional houses on the GameCube version. [PS2: 16:41] [GameCube: 30:55]

Beagle Boys:
Design change: Clouds are absent on GameCube, also there's an additional sun-ray effect. [PS2: 17:07] [GameCube: 32:49]

Design change: The background road is different on the left-side, and traffic seems to behave slightly differently depending on the version.

Level change: The box you are restricted to seems fairly smaller on the GameCube.

Design change: The wrecking ball casts a shadow on the GameCube, but not on the PS2. It's also more textured.

Camera change: The camera appears slightly higher on GameCube, though this might be because of the decreased area size.

Haunted general:
Design change: The PS2 sometimes has a green matrix hue whereas the GameCube has a blue Twilight hue.

Design change: Webs are clearly white on PS2 but a little more pinkish on GameCube.

Haunted 1:
Design change: There is a different background layout near the start. [PS2: 19:52] [GameCube: 37:00]

Design change: The ceiling is visible on the GameCube version at certain sections, but not on the PS2. Ex: [PS2: 20:49] [GameCube: 38:11]

Haunted 2:
Level change: A climbable bookcase is absent on the GameCube. [PS2: 22:50] [GameCube: 40:59]

Design change: The big duck statue is absent on the GameCube version. [PS2: 23:18] [GameCube: 41:30]

Design change: At the end of the level there are outside objects visible through the windows only on the PS2 version. The floor cut-off point is also straighter on GameCube. [PS2: 23:49] [GameCube: 42:03]

Haunted 3:
Design change: The outside area has a different skybox, and some objects (such as fallen trees) are tweaked differently between versions.

Magica DeSpell:
No obvious differences (aside from shading).

Fire general:
Design change: Trampolines light up when bounced upon on the PSN version, but not the GameCube version. This is the only difference I've ever noticed between the PS2 and the PSN, because they also don't light up on the PS2 version I've got, so this might be the only actual PAL/NTSC difference. [PS2: 40:22]

Design change: Various colour changes (platforms, lava, trampolines).

Design change: Flame shooters are somewhat easier to see on the GameCube version because of the way they stand out.

Fire 1:
No obvious differences.

Fire 2:
Design change: The closing/opening walls have a black rim at their base on GameCube.

Fire 3:
No obvious differences.

Fire 4:
Level change: An extra flame shooter is present on the right-side wall of the GameCube version at one point. [PS2: 38:12] [GameCube: 1:03:06]

Merlock:
Design change: The tornado is harder to see in the GameCube version because it is faded. [PS2: 39:45] [GameCube: 1:06:06]

In my opinion, the differences between the PS2, PSN, and GameCube versions do not merit a splitting of the category. The biggest level change happens on the very first level and it really doesn’t do much to affect play, other than requiring the player to need to jump a little extra. Other level changes are rather minor and don’t seem to pose much additional risk or slow the player down at all.