Unlock Superfrog
To unlock Superfrog, one of Team17's first characters, beat Puzzle mode with a completion rate of 100%.
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 the game in puzzle mode. As certain levels are completed (for example, Alien Attack), new modes in tournament mode will become unlocked.