Here is the full list of all 10 NekoChan Hero - there are Collection achievements.
Reach the end of the level with the bike
Reach the end of the level with the skateboard
Find all the special coins
Save the King
Kill the boss of the third castle
Reach the end of the level with the helicopter
Reach the end of the level with the watercraft
Kill the boss of the second castle
Reach the end of the level flying with balloons
Kill the boss of the first castle