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