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