During play, press….

Ctrl+c+oWins current campaign
Ctrl+g+oLoses current campaign
Ctrl+g+uHoming bullets
Ctrl+t+uTurbo speed
Ctrl+sColored 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!