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
Acquire all available upgrades
Buy a figurine
Stop Caesar's invasion plan
Beat the Caesars
Find all the diamond helmets
Find all the postcards
Beat 2500 Romans
Beat every type of Roman
Free Suchafuss
Finish a challenge at Gold rank
Open the door on Pirate Island
Find out who Getafix really is
Find all the diamond helmets on a level
Discover the fake Gaulish village
Beat 30 Romans in Fury mode
Beat 100 Romans under the effect of a magic potion
Stun 10 Romans at once
Obtain x6 multiplier
Pull the lever on the underground level
Bullseye!
Collect 9999 helmets
Free Kerosene
Gain access to LuckSore
Free Battermix
Gain access to Venitia
Buy an upgrade
Enter Las Vegum