Here is the full list of all 28 Asterix & Obelix XXL: Romastered achievements.
Complete stage 1 - Gaul
Get the maximum number of shields
Defeat 200 Romans under the effect of the magic potion
Strike a Roman in midair with Asterix under the effect of the magic potion when Obelix tosses a Roman
Keep the combo gauge full for 60 seconds
Retrieve a golden laurel
Switch between the REMASTER mode and the ORIGINAL mode
Complete stage 2 - Normandy
Complete stage 3 - Greece
Complete stage 4 - Helvetia
Complete stage 5 - Egypt
Complete stage 6 - Rome
Complete the entire game in ''Easy'' mode or at a higher level of difficulty
Complete the entire game in ''Normal'' mode or at a higher level of difficulty
Complete the entire game in ''Difficult'' mode or at a higher level of difficulty
Complete the entire game in ''Extreme'' mode
Defeat 5000 Romans
Buy all the combos from the merchant
Retrieve all the golden laurels
Complete all the course challenges
Complete a course challenge with more than 5 seconds to spare on the Gold level
Complete all the time challenges
Reach the Gold level in all the time and course challenges
Collect more than 99999 helmets
Spend more than 50000 helmets at the merchant's
Find and defeat Redbeard in each level
Complete all the course and time challenges
Sling yourself using rubber bands 20 times in less than 30 seconds