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