Hurt mother-in-law by biting her.
Take knife damage 100 times.
Catch 20 hearts.
Grab heart when you have 0 health.
Bite mother-in-law 125 times.
Unlock Kitty by earning 100 points as Froggy.
Unlock Crocco by earning 100 points as Kitty.
Score 100 points without taking damage.
Score 1000 points.