Standards
A: A quick sword swing.
AA/AAA: Basically Marth or Link's jab combo. Nothing special.
Up-tilt : Quick upward slash.
Down-tilt: like a spin attack, but more ground based.
Dash attack - A leaping strike like Link's dash.
Smashes
UpSmash: Spire - Creates a rock spire in front of Isaac depending on which way he is facing.
SideSmash: Move - A giant hand slowly moves left or right and pushes anyone away. Does no damage.
DownSmash: Earthquake - Large hitbox on the ground, can bury someone if they are close enough.
Specials
Neutral Special: Set Djinn - Isaac's main gimmick. Holding the special button will set a Djinni, up to 4 of them. All of Isaac's moves have increased damage and knock-back. Using a Smash or Special will use the Djinn and reset them, leaving a 15 second period before they can be set again.
Side Special: Slash - A quick slash of wind that gains more range depending on how many Djinn are set. Good for spacing.
Down Special: Blast - Creates an explosion with good knock-back. With all 4 Djinn, has range of a Smart Bomb.
Up Special: Deluge - Isaac rides on a wave of water. More range with more Djinn set.
FINAL SMASH - Judgement - Don't think this needs explanation