To enter cheats, quickly enter the following button presses while you're in any park. For most, you won't see any changes, but you will get results if you entered them right.

Code Effect

X,B.Y,X,B,Y,A $50,000
B,X,Y,B,X,Y,X 500 thrill points
X,B,Y,X,B,Y,B Activate mission unlock
X,B,Y,X,B,Y,right on d-pad Unlock all mini-games in Party Play
X,B,Y,X,B,Y,X Unlock all parks
X,B,Y,X,B,Y,Y Unlock all rides in current park

Unlockables - Complete each achievement to get the allotted gamerscore.

Bandito Beater (20) Complete Bandito Chinchilla.

Casanova (10) Become sweethearts with 10 park guests.
Challenge Champ (10) Win 10 challenges with park guests on any minigames.
Chatter Box (10) Fill your MyCrowd list.
Coaster Boaster (10) Design a rollercoaster.
Coaster Dropper (10) Build a coaster with a drop height of over 300 ft.
Coaster Speedster (10) Build a coaster with a top speed over 80 mph.
Crackshot (10) Get a X5 combo multiplier in a shooting gallery.
Critics (30) Complete the 'Bribery 101!' mission in Thrillville Stunts.

Disc Jockey (10) Collect all the Hypnodiscs.

Flippin' Great (10) Perform a 720 backflip in Stunt Rider.
Fore! (10) Complete a round of timed mini golf on hard.

Games Master (40) Complete all arcade games.

Hypnosis (30) Complete the 'Trance-Cendtal' mission in Thrillville Giant.

Karting Krazy (10) Come 1st in 20 races.
King of the Ring (15) Win a match by knockout on Robo K.O. without losing any health.

Lunar Lunatic (15) Complete Event Horizon 2 on hard difficulty.

Money Maker (10) Achieve a combined park value of $100,000

Party Dude (10) Play 20 party games with your friends.
Party Host (10) Complete a four player battle or co-op game in party play.
Perfect Clearance (15) Pocket all the balls in one turn at the table.
Propaganda (10) Collect all the anti-Thrillville propaganda boards.
Putt putt power (10) Design a minigolf course.

Robots (30) Complete the 'Clearance Sale' mission in Thrillville Otherworlds.

Sabotage (30) Complete the 'Alien Antics' mission in Thrillville Explorer.
Sideshow Superstar (20) Get a 5 star rating score on all sideshow games.
Smooth Move (10) Get a 60 note combo in the entertainer mini game.
Sparkling Secret (10) Discover all the secret areas on Sparkle Quest level 1.
Spoon Time (15) Get 30.000 points in 3 moves on Trampolines.
Sprint King (15) Get a best lap time under 4'90" seconds on the first track on Autosprint 2.
Squadron Ace! (20) Complete Squadron Ace.
Stunt Rider! (20) Complete Stunt Rider.
Super Sparkler (20) Complete Sparkle Quest.

Tank Commander (20) Complete Tank Frenzy.
Teamwork (10) Complete a minigame in coop mode.
The Green (10) Find all Mortimer’s cash drops hidden in all parks.
The Rainbow (10) Collect all the Nano Paint Sprayers.
Thrillville Explorer (40) Unlock Thrillville Explorer.
Thrillville Giant (40) Unlock Thrillville Giant.
Thrillville Holiday (50) Unlock Thrillville Holiday.
Thrillville Otherworlds (40) Unlock Thrillville Otherworlds.
Thrillville Phenomenon (60) Reach park owner level 10.
Thrillville Sensation (40) Reach park owner level 5.
Thrillville Superstar (50) Rank in the top ten on any online leaderboard for Thrillville: Off the Rails.
Thrillville Talent (20) Reach park owner level 2.
Traitor (30) Complete the 'Traitors Arena' mission in Thrillville Holiday.

UFO Survivor (15) Survive without being knocked out of the arena in Saucer Sumo on normal difficulty.

White Knuckle Ace (10) Build all WHOA pieces.
Whoa (10) Finish a coaster using a whoa piece.
Winner! (20) Successfully win 20 multiplayer battle games.