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