As someone who also used pixel art, ensure choosing (Point, No Filter) and compression (None) when importing them over. Adjust the Pixels Per Unit to a size that your character should fit in (if the sprite is 64 pixels and you want it to take 1 Unity unit, set it to 64).
Other than the sprites, I think the game is way too hard. The basket moves way too slow to match the speed of the falling birds and cats, though it is funny for me to catch falling birds.