Here is the full list of all 30 Asterix & Obelix XXL 2 achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Reach 100% completion
Finish all challenges at Gold rank
Buy all the figurines
Beat 2500 Romans
Acquire all available upgrades
Finish a challenge at Gold rank
Stop Caesar's invasion plan
Beat the Caesars
Find all the diamond helmets
Beat every type of Roman
Find all the postcards
Free Suchafuss
Open the door on Pirate Island
Find out who Getafix really is
Discover the fake Gaulish village
Pull the lever on the underground level
Beat 30 Romans in Fury mode
Bullseye!
Free Kerosene
Buy a figurine
Buy an upgrade
Collect 9999 helmets
Gain access to LuckSore
Free Battermix
Find all the diamond helmets on a level
Beat 100 Romans under the effect of a magic potion
Gain access to Venitia
Obtain x6 multiplier
Stun 10 Romans at once
Enter Las Vegum