Finish the game to unlock the "End Level" cheat. This allows you to end the level in missions and mini-games.
Jungle level in multi-player mode
Rescue the two women in the Jungle level to unlock the level in multi-player mode.
Unlock Super Agent
Complete the game to unlock "Super Agent" mode. Pause the game to access the options menu and enable the "Super Agent" option. In this mode, all shots are one-hit kills.