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