Shoot down 1000 ducks to unlock the "Cheat Menu" button at the lake menu. Click on the button to access the following options after they have been unlocked.
Unlimited ammunition
Enter the cheat menu. The "Infinite Ammo" option is already available by default.
No ducks missed
Enter the cheat menu. The "No Missed Ducks" option is already available by default.
Slower ducks
Shoot down 250 ducks in Evening Lake. The "Slower Speed" option is now unlocked in the cheat menu.
Space Shooter mini-game
Shoot down 250 ducks in Dark Lake. The "Space Shooter" option is now unlocked in the cheat menu.
Challenge mode
Get a ranking on Legend. The "Challenge Mode" option is now unlocked in the cheat menu.
Master code
Note: This code requires v1.01 or higher. Click the "Start" button at the title screen, then enter EXPERTHUNTER as a name. All cheats, a Legend ranking, and all the lakes will be unlocked.