Here is the full list of all 36 Rick Henderson achievements.
Collect 2500 Gems
Kill 20000 Enemies
Enter Minefield 10 Times
Enter Asteroid Field 10 Times
Enter Meteor Storm 10 Times
Kill 100 Bosses
Break Warp 10 Times
Enter Laser Barrage 10 Times
Kill 10000 Enemies
Collect 1000 Gems
Collect 1000 Ranks
Kill 50 Bosses
Kill 5000 Enemies
Collect 500 Gems
Attain Commander Rank
Kill 2500 Enemies
Attain General Rank
Attain Marshal Rank
Kill 100 Transports
Attain Colonel Rank
Attain Major Rank
Kill 1000 Enemies
Collect 100 Gems
Attain Captain Rank
Kill 10 Bosses
Kill 750 Enemies
Kill 500 Enemies
Finish A Loop
Attain Lieutenant Rank
Kill 250 Enemies
Attain Sergeant Rank
Attain Corporal Rank
Attain Private Rank
Kill 100 Enemies
Kill 50000 Enemies
Collect 5000 Gems