Optional weapons:
Go to the Weapons Screen. Once there, press Square and X buttons simultaneously 8 times and you will see that some of the standard weapons will be replaced by Banana Bombs, Sheep Bombs, and a minigun.

Indian rope trick:
Select the Ninja Rope, aim the cursor down, face right, fire rope, adjust height up or down.

Boxing Ring:
While playing, execute a fire punch or a dragonball, then quickly hold SQUARE and press R1, L1, Circle. If you did it correctly, one worm from each team will be teleported to a boxing ring where all you can do is punches and dragonballs. When one of the worms dies you will teleport back to the original landform.

Infinite banana bombs:
If you go to the weapons options screen and hit Down, Right, X, Square, Square, X, Square, Square, X, Square, Square you will recieve infinite banana bombs. NOTE: not for use with the upgraded weapons code (X + Square 8 times).

Change landscapes:
When you start a game of Worms, a new landscape is randomly generated. However, using these codes, you can choose what neighborhoods you frequent. Press X to clear the preset code when a landscape is being generated at the start of a game. Pres Up or Down to cycle through letters and numbers and right to go to the next slot in the code. When the code is entered, press X to generate the new landscape:

00956 -- Desert Storm
29726 -- Low Bridge
46463 -- Martianscape
57805 -- Another Martianscape
70345 -- Lollipop
97155 -- Three's a Crowd
149147 -- Kill Smiley
208041 -- Alternate Jungle
326576 -- Crowded Alienscape
436642 -- Hell
4802043 -- A Bridge Too Far
5154527 -- Lollipop Bridge
7007230 -- Snow Joke
7841228 -- Beach
13410325 -- Life's A Beach
23418990 -- All Beached Up
CHEZZY -- Hollow Mountain
39054687 -- Beach Weather
56439996 -- The Tide is High
62332782 -- Forestscape
77004498 -- Alienscape
99426730 -- Cliffs of Hell
203953110 -- Alien Bridge
223981979 -- Christmas Tree
309072302 -- Jungle Island
635199159 -- Cliffs and Lake
733737544 -- Another Alienscape
742182075 -- Another Forestscape
954338916 -- Bless You
1408066876 -- Another Candyscape
3329407250 -- Snorkel Island
7373888390 -- Fires of Hell
8902118313 -- Jungle
THORAHIRD -- Dig Carefully

MORE WACKY LANDSCAPES:

33926
4802043
6786876866
WORMS RULE
37637177
7267896
7373888390
37637177
7267896
7373888390
70345
43692833
BRITISH
80765
223981979
KIG IS COL
304768
903172603
DOOM SUCKS