Play As Bruno - If you collect all picture frames, you'll have access to Bruno from Die Hard. 

Unlimited Credits & Tranquilizer Gun - Complete Missions 1, 2 & 3 without using all of your continues. 

Be Monkey - Complete missions 4, 5 & 6. 

Be Original Bruno - Obtain all illustrations. 

Get Tranquilizer Gun Mini Game - Beat the Game 1 time. 

Extra Missions - Complete missions 1, 2, & 3 without using continues.

Gameshark Codes

P1 High Score of 9999999
F4F99D10  0000967F  3B292FD1  00000098

P1 Infinite Health
9DE0016C  00000064

P2 High Score of 9999999
1A641D00  0000967F  42A21458  00000098

P2 Infinite Health
96500161  00000064