Here is the full list of all 36 Tony Hawk's Pro Skater 1 + 2 achievements.
Reach Career level 100.
Complete all "Hard" Get-Theres.
Complete all Gap collections.
Earn the "Legend" Challenge Collection.
Earn 2,000,000 points in Combo Mambo across all playtime.
Earn 5,000,000 points in Trick Attack across all playtime.
Give 50 Letters in Horse.
Earn the "Veteran" Challenge Collection.
Find every alien plushie.
Find all Stat points for any Pro Skater.
Unlock Officer Dick.
Place 500 objects in CAP.
Create a new park and upload it.
Earn a score of 10,000,000 in any park in a 2 minute session or single combo. Game Mods must be disabled.
Land a 1,000,000+ point combo.
Achieve a High Score of 1,000,000+ on any classic Park.
Spend $10,000 in the Skate Shop.
Paint 100 surfaces in Graffiti across all playtime.
Complete every goal in THPS2 Classic and gain all gold medals.
Get hit by a vehicle on every map that features them.
Complete every goal in THPS1 Classic and gain all gold medals.
Get hit by the Bull in Bullring.
Unlock Bullring in THPS2 Classic.
Earn any 4 Medals on competition parks in Tours.
Unlock School II in THPS2 Classic.
Unlock Roswell in THPS1 Classic.
Achieve a judge score of 99.9 on a competition run.
Earn the "Rookie " Challenge Collection.
Break 20 Panes of Glass.
Complete a match in multiplayer.
Bail a 100,000+ point combo.
Reach Career level 10.
Land a 50,000+ point combo.
Earn a Medal on any competition park in Tours.
Unlock School in THPS1 Classic.
Create a skater using the CAS system.