Et bien, un coup de chapeau à l'équipe de Team 17 qui s'est fait un point d'honneur à répondre à mon mail dans la journée !
Voici leur réponse:
"Hello,
Thankyou for contacting us here at Team17, we found this email to be most amusing.

It was very hard to find someone who could remember what parameters went into deciding the awards at the end of a game. It turns out that a lot of different coders over the years have had their own input and the actual rules are almost impossible to decipher. There are quite a number of different awards, but only so much space on screen, so the actual awards to be given out were picked at random and at some point it was requested to see more of the most entertaining worms award, so that was given a lot more importance.
Factors that influenced awards are just what you would expect, for example Boring worms would be those using girders, tunnelling and skipping go. Greedy worms would be those picking up the most crates and entertaining worms would be those doing cool long shots and killing multiple worms with 1 shot.
So, you could get an instance where the greedy worm award was picked at random and if only 1 crate was picked up, the award would be given to that worm, which would seem a bit strange.
Sorry I couldn't shed more light on this for you and thanks again for writing to us and sparking off a quite interesting trip down memory lane for some of us.
Regards"
Bon, ceci correspond plus à une explication concernant les mécanismes d'attribution des récompenses, mais on peut en déduire que le système de score est finalement un peu tombé dans l'oubli

J'ai quand même répondu en reprécisant ma requête, on verra bien ce que ça donne.
"Thanks a lot for your quick answer !
My question was actually more about the score (sorry for my english), and I meant the number of 'points' you may get in the end of the match.
But as I understand your message, the underlying mechanisms would be unclear as well ;)
However, I guess this just adds even more fun for the game ;)
A mystery which is never gonna be solved?
Anyway, thanks again for your involvement, please keep having fun and providing amazing games like u've always done.
Have a nice week."