PC - Windows Cheats: Worms Blast Cheats

All secret characters
At the start screen (the screen before the main menu), hold [Left Shift] and press [Up] four times, [Down] three times, [Up] five times.

Bonus characters
Successfully complete all puzzle mode levels. Go to the volcano level in the middle to unlock Fletcher, Rocky, and Superfrog.

All tournament modes
Play through puzzle mode. As certain levels are completed (for example, Alien Attack), new modes in tournament mode will become unlocked.