Is it possible to unlock weapons/settings/cheats in WWP like you can in W:A? Like invinciblility and stuff like that. If so, how do you do it?

No, in WWP you already have everything right from the start.
Nothing to unlock. Nothing to earn after finishing the missions.

And on top of that, the indestructable terrain option is missing in WWP.
(You need an external scheme editor to enable it.)

You should have bought W:A.

In wwp for computer there is no Low Gravity, but on the PSX it is there...I wonder why that is. The graphics folder on the PC even has the icon!

time of release may be why it isnt in the pc version.

According to SupSuper's WormPot FAQ (http://supremesuper.tripod.com/WormZone/Eng/HTML/my_wormpot.html#on_the_moon) Kilburn (http://forum.team17.co.uk/member.php?u=199) said this:
The On the Moon mode is only available on the PlayStation version of Worms World Party.

I think I vaguely memorize that some other teamster (Spadge?) mentioned that they left it out because people may overlook the small icon on the bottom left if it is activated permanently.

Don't know why it is in the Playstation version though. Maybe that one was ported by a different company?
For exampls the WWP version for GBA has all the left out weapons from W2 in it and also a complete new one (a chainsaw).

I wonder if On The Moon is available in the Dreamcast version of WWP, as I think that was the first version to be made/released, then "ported" back to PC and the rest, if I'm not totally wrong.

Low Gravity most definitely is a utility in the PC version of WWP. That is, however, not to be mixed with the On the Moon Wormpot option, that makes low gravity permanent during the whole match.

Just to make this thread a bit more clear.

Nah, I wouldn't say that. W:A's wormnet is pretty much exclusively played by those who are already skilled and have contacts.

WWP's wormnet on the other hand is a much more newbie-friendly place, to put it nicely.
Nonsense..
Another period so it'll have 10 letters in the post.

You should have bought W:A.
Nah, I wouldn't say that. W:A's wormnet is pretty much exclusively played by those who are already skilled and have contacts.

WWP's wormnet on the other hand is a much more newbie-friendly place, to put it nicely.

not true wa also has noobs, i play em all the time not to mention I'm no skilled pro myself.

and i try and bring love to wa, i say hello to everyone and stuff BP.F.B.L - BoggyPants For Brotherly Love