Normal Rick:

Punch U - All punches do 8 damage. Full combo: 32 damage Punch J - 4 punch combo does 8, 8, 8, 40 in that order. Full combo: 64 damage

Spinkick U - 80 damage. 64 on "big" enemies. Spinkick J - 8 damage, but only 1 rotation, so much faster. Only really useful for crowd control.

Mutant Rick:

Punch U - 3 punch combo does 8, 16, 40 in that order. Full combo: 64 damage Punch J - 3 punch combo does 16, 40, 80 in that order. Full combo: 136 damage

Breadsticks U - 248 damage. 120 on "big" enemies. Breadsticks J - 80 damage and it consumes ~25% of your POW meter. Only worth it when you're about to revert back to Normal Rick or if it will kill everything before your POW runs out.

*Also note that both the spinkick and breadsticks use attack+jump to perform the moves in the JP version.