Bam Margera: Successfully complete his Pro Challenge
Beaver mascot: Unlock the High School
Bob Burnquist: Successfully complete his Pro Challenge
Bum: Unlock the Car Factory level
Daewon Song: Successfully complete his Pro Challenge
Dustin Dollin: Successfully complete his Pro Challenge
Filmer: Unlock the High School level
Jason Lee: Successfully complete the final Tony Hawk goal
Lyn-z Adams Hawkins: Successfully complete his Pro Challenge
Mike Vallely: Successfully complete his Pro Challenge
Nyjah Huston: Successfully complete his Pro Challenge
Paul Rodriguez: Successfully complete his Pro Challenge
Photographer: Unlock the Shops level
Real Estate Agent: Unlock the Downtown level
Rodney Mullen: Successfully complete his Pro Challenge
Ryan Sheckler: Successfully complete his Pro Challenge
Security Guard: Unlock the School level
Stevie Willams: Successfully complete his Pro Challenge
Travis Barker: Successfully complete his Pro Challenge
Zombie: Successfully complete his Pro Challenge

All Pros Behind The Scenes: Successfully complete all Pro Challenges.
All Pros Day In The Life: Obtained from Jason Lee once each time.
Bam Margera Pro Footage: Successfully complete the Bam Margera Pro Challenge.
Bob Burnquist Pro Footage: Successfully complete the Bob Burnquist Pro Challenge.
Daewon Song Pro Footage: Successfully complete the Daewon Song Pro Challenge.
Dustin Dollin Pro Footage: Successfully complete the Dustion Dollin Pro Challenge.
Lyn-Z Adams Hawkings Pro Footage: Successfully complete the Lyn-Z Adams Hawkings Pro Challenge.
Mike V Pro Footage: Successfully complete the Mike V Pro Challenge.
Nyjah Huston Pro Footage: Successfully complete the Nyjah Huston Pro Challenge.
Paul Rodriguez Pro Footage: Successfully complete the Paul Rodriguez Pro Challenge.
Pro Bails 1: Successfully complete the Tony Hawk Pro Challenge.
Rodney Mullen Pro Footage: Successfully complete the Rodney Mullen Pro Challenge.
Ryan Scheckler Pro Footage: Successfully complete the Ryan Scheckler Pro Challenge.
Stevie Willams Pro Footage: Successfully complete the Stevie Willams Pro Challenge.

Skate over to the large roller coaster. Enter at the entrance of the roller coaster, skating in the opposite direction of the cart. Fully skate the roller coaster while jumping over the cart when it comes around and land at the beginning of coaster entrance. Do not fall and land it to get a few hundred Stokens.

Training Complete (10 points): Complete the training.
Outta the houses (10 points): Escape the suburban life.
School unlocked (10 points): Unlocked the School.
Slums unlocked (10 points): Unlocked the Slums.
Skate Park unlocked (10 points): Unlock the Skate Park.
Funpark unlocked (10 points): Unlock the Funpark.
Factory unlocked (10 points): Unlock the Factory.
First Sick Goal (5 points): Complete a goal at Sick difficulty.
All pro challenges completed (20 points): Complete all the pro’s challenges.
Sick Chalk Challenges (30 points): Complete all the goals at Sick difficulty.
Sick Classic Goals (30 points): Complete all the classic goals at Sick difficulty.
Hit 50% of the gaps (20 points): 50 percent of the gaps found.
Hit all of the gaps (35 points): Skate the world and find every gap.
Scored over 1,000,000 points! (10 points): Score over 1 million points.
Nice combo! (20 points): Land a combo over 500,000 points.
Played Xbox Live (10 points): Play an online game.
50 games online (15 points): Finish 50 games online.
100 games online (20 points): Finish 100 games online.
You made it into Project 8 (50 points): Crack the top 8.
You made it to spot 4! (75 points): Crack the top 4
Ranked Number 1! (100 points): You are the number one skater on Project 8.
Secret area found (5 points): Find your first secret area. Don’t tell anyone.
Manual Master (20 points): Manual for 140,000 feet..
Hang Time (20 points): Get 14,000 seconds of air time.
The Daily Grind (20 points): Grind for 140,000 total feet.
Beat a developer (50 points): Win a skate session against a member of the Project 8 development team, or someone who already has.
Suburbia Classic beaten at sick. (15 points): Get sick on the Suburbia classic goal.
Main St Classic beaten at sick (15 points): Get sick on the Main St classic goal.
Capitol Classic beaten at sick (15 points): Capitol Classic beaten at sick.
School Classic beaten at sick (15 points): Get sick on the School classic goal.
Slums Classic beaten at sick (15 points): Get sick on the Slums classic goal.
Skate Classic beaten at sick (15 points): Get sick on the Skate Park classic goal.
Fun Park Classic beaten at sick (15 points): Get sick on the Fun Park classic goal.
Factory Classic beaten at sick (15 points): Get sick on the Factory classic goal.
Full stats (50 points): Get every stat maxed.
Mullen Pro Challenge (10 points): Find Rodney and beat his challenge.
Vallely Pro Challenge (10 points): Find Mike V and beat his challenge.
Song Pro Challenge (10 points): Find Daewon and beat his challenge.
Burnquist Pro Challenge (10 points): Find Bob and beat his challenge.
Sheckler Pro Challenge (10 points): Find Ryan and beat his challenge.
Margera Pro Challenge (10 points): Find Bam and beat his challenge.
Nyjah & Lyn-Z Pro Challenge (10 points): Find Nyjah and Lyn-Z and beat the challenge.
Williams & Dollin Pro Challenge (10 points): Find Stevie and Dustin and beat the challenge.
P-Rod Pro Challenge (10 points): Find P-Rod and beat his challenge.

Additionally, there are five secret achievements:

Break 15 Bones In One Bail (10 points): Self-explanatory.
Impressing The Locals (25 points): Get 1000 Stokens.
Shhhh it’s a secret (25 points): Find all the secret areas.
Sick Highscore Run (20 points): 5,000,000 point combo in High Score/Free Skate.
That combo was sick! (35 points): Land a combo over 5,000,000 points.

Bone Breaker (5 points): Kill 30 enemies with thrown physics objects.
Deadly Harvest (5 points): Kill an enemy by planting a hopper mine.
Hack Attack! (5 points): Kill five enemies with a Manhack.
Hot PotatOwned (10 points): Kill a Combine soldier with his own grenade.
Conservationist (5 points): Kill five enemies with the same energy ball.
Think Fast! (10 points): Kill an Elite Soldier with his own energy ball.
Grave Robber (5 points): Steal a Zombine’s grenade.
Zombie-que (5 points): Use flares to light 15 zombies on fire.
Malcontent (5 points): Escape the apartment block raid.
What cat? (5 points): Break the mini-teleporter in Kleiner’s lab.
Trusty Hardware (5 points): Get the crowbar.
Barnacle Bowling (5 points): Kill five barnacles with one barrel.
Anchor’s Aweigh! (5 points): Get the airboat.
Heavy Weapons (5 points): Get the airboat’s mounted gun.
Vorticough (13 points): Discover the hidden singing vortigaunt cave in chapter Water Hazard.
Revenge! (10 points): Destroy the hunter-chopper in Half-Life 2.
Blast from the Past (10 points): Find the HEV Suit Charger faceplate in Eli’s scrapyard.
Zero-Point Energy (5 points): Get the Gravity Gun in Black Mesa East.
Two Points (2 points): Use DOG’s ball to make a basket in Eli’s scrapyard.
Zombie Chopper (25 points): Play through Ravenholm using only the Gravity Gun.
OSHA Violation (5 points): Kill 3 enemies using the crane.
Targetted Advertising (5 points): Pin a soldier to the billboard in chapter Highway 17.
One Man Army (5 points): Destroy six gunships in Half-Life 2.
Keep Off the Sand! (20 points): Cross the antlion beach in chapter Sandtraps without touching the sand.
Bug Hunt (10 points): Use the antlions to kill 50 enemies.
Flushed (5 points): Kill an enemy with a toilet.
Warden Freeman (10 points): Survive the second turret standoff in Nova Prospekt.
“Radiation Levels Detected” (5 points): Get through the toxic tunnel under City 17 in Half-Life 2.
Plaza Defender (10 points): Survive the generator plaza standoff in chapter Anticitizen One.
Counter-Sniper (5 points): Kill all of the snipers in City 17.
Fight the Power (10 points): Shut down the supression device by disabling its generators.
Giant Killer (10 points): Survive the rooftop strider battle in the ruins of City 17.
Lambda Locator (15 points): Find all lambda caches in Half-Life 2.
Watch Your Head! (5 points): Make it to the bottom of the Citadel’s main elevator shaft in one piece.
Containment (5 points): Contain the Citadel core.
Pacifist (10 points): Contain the Citadel core without killing any stalkers.
Car Crusher (5 points): Use the cars to squash 15 antlions in Half-Life 2 Episode One.
Elevator Action (10 points): Survive long enough to get on the parking garage elevator.
Live Bait (10 points): Help Alyx snipe 30 enemies in Half-Life 2 Episode One.
Attica! (5 points): Destroy the gunship in the hospital attic.
Citizen Escort (15 points): Don’t let any citizens die when escorting them to the escape train.
Escape From City 17 (20 points): Escape City 17 with Alyx.
The One Free Bullet (40 points): Beat Episode One firing exactly one bullet. Grenade, crowbar, rocket, and Gravgun kills are okay.
Acid Reflex (5 points): Kill an Acid Antlion worker.
Get Some Grub (20 points): Squish every Antlion Grub in Half-Life 2 Episode Two.
Pinata Party (5 points): Find and break every web cache in Half-Life 2 Episode Two.
Into the Breach (5 points): Help Griggs and Sheckley hold off the Antlion invasion inside the mine shaft.
Hit and Run (5 points): Run over 20 enemies with the car in Half-Life 2 Episode Two.
Puttin’ On a Clinic (15 points): Defeat the chopper in Half-Life 2 Episode Two without any misses.
Cache Checker (10 points): Find every radar cache in the Under The Radar chapter.
Gordon Propelled Rocket (5 points): Unlock the rocket launcher lambda cache in the Under The Radar chapter.
Pedal to the Metal (5 points): Beat DOG in a race to the White Forest base.
Little Rocket Man (30 points): Send the garden gnome into space.
Neighborhood Watch (35 points): Save all buildings outside the missile silo from destruction.
Payback (10 points): Kill a Hunter with its own flechettes.
Lab Rat (5 points): Acquire the fully powered Aperture Science Handheld Portal Device in Portal.
Fratricide (5 points): Do whatever it takes to survive in Portal.
Partygoer (5 points): Make the correct party escort submission position decision in Portal.
Heartbreaker (10 points): Complete Portal.
Terminal Velocity (5 points): Fall 30,000 feet in Portal.
Long Jump (5 points): Jump 300 feet in Portal.
Cupcake (10 points): Beat two Portal advanced maps.
Fruitcake (20 points): Beat four Portal advanced maps.
Vanilla Crazy Cake (30 points): Beat all six Portal advanced maps.
Basic Science (10 points): Earn bronze medals on all Portal challenges.
Rocket Science (20 points): Earn silver medals on all Portal challenges.
Aperture Science (40 points): Earn gold medals on all Portal challenges.
Turret (5 points): Accumulate 10 turret kills with a single turret.
Nemesis (5 points): Get five revenge kills.
Hard to Kill (10 points): Get five kills in a row without dying.
Master of Disguise (15 points): Trick an opposing medic into healing you.
With Friends Like these… (10 points): Play in a game with seven or more players from your friends list.
Dynasty (10 points): Win 20 games.
Hardcore (15 points): Accumulate 1000 total kills.
Powerhouse Offense (5 points): Win 2Fort with a shutout.
Lightning Offense (10 points): Win Well in 5 minutes or less.
Relentless Offense (20 points): Win Hydro without giving up a capture.
Impenetrable Defense (10 points): Successfully defend Dustbowl without giving up a capture.
Impossible Defense (30 points): Successfully defend Gravel Pit without giving up a capture.
Head of the Class (5 points): Play a complete round with every class.
World Traveler (5 points): Play a complete game on every map.
Team Doctor (5 points): Accumulate 25000 heal points as a Medic.
Flamethrower (5 points): Set five enemies on fire in 30 seconds.
Atomizer (10 points): Disintegrate 15 soldiers by throwing them into a Combine ball field.
Follow Freeman (10 points): Gain command of a squad of rebels in the uprising.
Grey Matter (5 points): Get 25 headshots as a Sniper.
Camera Shy (5 points): Detach security cameras from the walls.
Friendly Fire (5 points): Knock down a turret with another turret.

Additionally, there are eleven secret achievements, nine of which are currently unknown.

Defiant Achievement (5 points): At the beginning of Half-Life 2 where the carbine cop asks you to pick up the can, pick it up and hit him with it.
Submissive (5 points): Put the can in the trash in Half-Life 2.