What were the changes between Wii version and PC remake?

[Taisetsu na Miko]

The faery clothes seem to reduce only 1/4 or a third of all damage, but it says that it is supposed to half damage. Was this the same in the Wii version which seems a lot easier?

[GeminiSaint]

I'm pretty sure it's half damage.
I do own the WiiWare version (US region). The biggest changes that I noticed are:

-No Hell Temple (present in Japan as DLC).
-No Time Attack modes (also present in Japan as DLC).
-No large skull graphic effect when activating hard mode.
-All three developers' secret messages are different and full of Engrish.
-Unread tablets don't glow.
-English and Japanese are the only two language options.
-No random crash during the early moments of Mother's final form.
-The fake wall in Graveyard C-1 is one platform higher, which makes it unreachable if the player messes up the ice block switches. To balance this, an extra passageway leading to the save tablet exists in room D-6 (in the form of a bombable section of the floor near the boobytrap chest).

That's pretty much it, I think.

[Taisetsu na Miko]

It definitely is not 1/2 damage. Just going into Time Attack will prove it. The blue giant (Argus I think) takes 11 damage when you have the faery clothes, but he takes 16 damage without them. That looks a lot like 1/3.
You missed a very important change I did know about - Palenque has a life draining effect in the PC version. Without it, he was quite weak.

[GeminiSaint]

Also, I forgot to mention there are fewer save slots in the WiiWare version. Four, if I remember correctly (I don't feel like hooking up the Wii to check).

[Allaze-Eroler]

there is another change which you didn't noticed: some statue that represent the woman have their nipples removed or hidden in the pc version while the wii version have their nipples shown. it would be a good idea to look into it and see what is more change it does have.

[Dokapon Kingdom Fully Modded]

Isn't the first puzzle in Gate of Illusion different?