Press Jump + Y to have Obelix do a body slam to the ground. Note: This will not affect Bosses.
Defeating the Battalion
Jump into the middle of the Battalion and repeatedly press A until they explode.
Defeating The Norse Hammer
Pause game play during the battle with the Norse Hammer, then press B to advance past the fight.
Defeating the Roman Spy
Repeatedly press A until he disappears.
Hit enemies with each other
Approach an enemy, hit them once, then press Y. Asterix will swing them around. Have Obelix throw an enemy towards you. If timed correctly, you can press Y and swing another enemy around, hitting the other opponent. A 10X modifier will appear.
Throw and hit opponent
Press L(2) to have Obelix to swing and throw an opponent to Asterix. Hit them before they touch the ground to instantly destroy them. Hit the opponent just after Obelix throws him (while they are in the air), and Asterix will glow and a 3X modifier will appear.
Unlockable costumes
To unlock extra costumes for Asterix and Obelix, collect all Gold Laurels in a Roman province.