Here is the full list of all 30 Asterix & Obelix: Slap them All! achievements.
Complete a mission playing only as Obelix.
Stun 5 enemies at the same time.
Complete Act 1 “Asterix in Britain”.
Complete a mission playing only as Asterix.
Ram 10 enemies with a single charge.
Complete the first mission.
Complete Act 2 “Asterix and the Normans”.
Complete Act 3 “Asterix in Spain”.
Complete Act 4 “Asterix in Corsica”.
Complete Act 5 “Asterix and Cleopatra”.
Complete Act 6 “The Revenge of Julius Caesar”.
Complete the adventure mode on the Easy difficulty (or higher).
Complete the adventure mode on the Medium difficulty (or higher).
Complete the adventure mode on the Hard difficulty (or higher).
Complete the adventure mode on the Hardest difficulty.
Complete mission 6-1 "Rally the Galleys" without getting hit even once (Medium difficulty or higher).
Complete Mission 6-8 “Morituri te salutant” without picking up any food (Medium difficulty or higher).
Send 5 enemies flying with a single uppercut.
Knock down 10 enemies with a single throw.
Complete a mission in Freeplay mode.
Destroy all barrels in Mission 5-2 “Risky Business”.
Destroy all barrels in Mission 3-4 “Holding Out in the Hold” in under 35 seconds.
Destroy all objects in Mission 6-5 “Stomping Through Italy” in under 80 seconds.
Send an enemy flying in the air before it ever touches the ground.
Land 40 hits in a row with a single spin with Asterix.
Score at least 500,000 points on any mission.
Make the Slap Count climb to over 600.
Start a mission in co-op mode.
Use all of Asterix’s attacks in a single mission.
Use all of Obelix’s attacks in a single mission.