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