During play, press….

Ctrl+c+o	Wins current campaign
Ctrl+g+o	Loses current campaign
Ctrl+g+u	Homing bullets
Ctrl+t+u	Turbo speed
Ctrl+s		Colored smoke 

All crafts:

At the pilot screen, hold down Left Ctrl and Right Ctrl while choosing a plane to gain access to every plane and/or helicopter in the game.

Thanks to Revolution readers Bliamba, David Burns, and Ershad!