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