10,000 cash
During the game move the thumbstick as follows - Down, Up + Left Trigger (at the same time). You will receive a "cheat activated" screen when done correctly.

Unlock Site B
Defeat every mission in the game to unlock site B at the main menu.

Dino Rampage
While playing a game, press L(3), Left(3) to make all carnivores in your park stressed.

Market Day
Tap the triggers L and R at the same while pressing left, right, down. If you do it correctly you should be able to get a whole lot of fossils you can buy at the fossil market!

No Twisters
Use analog stick and press the triggers L and R at the same time while going from left to right each one time while using the analog stick, you may have to do it a second time.

Money Market
Tap L and R at the same time while pressing analog stick or whatever you wish to use two up and two down, if you entered it correctly you should have a whole bunch of bones ready to buy on the market.

Seqencing Error
While tapping the triggers L and R tap left, up, down. This is something a bit tricky so don't get frustrared the first time, keep on trying and you soon will get it.

Impossible Mission
While playing a game, press Right(3), R.

All Research
Press: Down, Down, Down, Left, Right, L, Down, Up.

Guaranteed Immunity
While playing a game, hold L + R and repeatedly tap Up. Dinosaurs will no longer get sick. In the PAL version of the game, press Up(2), R, L, Up(2) while playing game.

Gimme Some Money
While playing game, press L + Up, L + Down. $10,000 will be added to your finances.

Where's The Money?
While playing game, press L + R, Down. Your finances will be reduced to zero. Alternately, press L, R, L, R, Down(2) while playing game.

Crash!
While playing a game, hold L + R and repeatedly tap Up, Down, Up, Down. One of your safari cars will blow up. Alternately, press R, L, Up, Down, Up, Down while playing game.

Oh No!
While playing a game, hold R and press Right, Left, Right, Left, Right. All tourists will die. Alternately, press Left, Right, Left, Right, R while playing game.

More visitors
If you want more people to visit your park, build four or five entrances on all different sides.

Avoiding visitor deaths
Never build a Safari Adventure in your T-Rex cage. The visitors inside of the car will not live too long. Also, never put more than one T-Rex in one cage. One will be killed and the other badly injured; and the visitors around the cage will get scared to death. This costs you a lot of money, for the T-Rexes and the fines.

Driveby
Press - R + L, Left, Down, and Right[x2] to shoot from the Safari cars by using the camera.

Exodus
Press L, R, L, Right, Down, R.

Extinction Event
Press L, R, Down, R, and L to kill all dino's.

Hot One
Press - R + Down and R + Down to cause a heat wave.

Impossible Mission
Press - R, Right[x4], and R to unlock all missions, exercises, and sites.

Instant Alcatraz
Press: L, Left, Left, R, R, Right.

Isla Muerta
Press - R[x3], L, and Right to make the dino's look like the living dead.

Minimum Security
Minimum Security press: Down, Down, Left, Right, L, L, Up, Up.

Mr. DNA
Press R, Up, R, Right, L, and Down to set all excavated dinosaur DNA to 100%.

No Red Tape
Press - L, R, Left, and Down[x4].

Ooops....
Press: Up, R, Down, L, Left, Left.

Open To The Public
Press - Left, Down, Right, Up, L + R, and L + R to freely select three dig sites without any stars.

Pax Jurassicus
Press: L, Left, Up, Left, Up, Left, L.

Plague Outbreak
Press: Down, Up, Down, Left, R, R, R.

Psycho dinos
During the game hit L, L, L, left, left, left.

Ramage Time
Press - L[x3] and Left[x3] to stress out all Carnivores.

Rocky Road
Press: Right, Right, R, R, L, Down.

Seal of Approval
Press: Right, L, Up, L, L, Down.

Storm Free
Press: R, R, Left, Right, Up, Right.

Three Stars
Press: L, R, Down, Down, L, Right.

Welcome To Melbourne
Press R[x2], L, R, Down, Up, and Down to cause stormy weather.

Welcome to Sydney
Welcome to Sydney press: R, L, R, Down, Up, Down.