What is a difference between Super Mario Galaxy 1 and Super Mario Galaxy 2?

well super Mario galaxy 1 doesnt have Yoshi and super Mario galaxy 2 does.super Mario galaxy 2 has an icon for rossalina when you get 240 stars. super Mario galaxy 2 has coment medals which you get in the gane in all the galaxys super Mario galxy 1 you can play as Mario and lugi but in order to play as lugi you have to get 120 stars as Mario and in super Mario galaxy 2 you can play as luigi after you beat tall trunk galaky.