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