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