Upgrade suggestion

Ok i love the game but i hate the fact that u lose old upgrades when u get a new one. A suggestion: Why dont u have a menu that u can go to that u can change the upgrade u would like to use. U could access any upgrade that uve got at the begining of the level. Its not an upgrade if u lose the old upgrade so dwell on all these comments and add something like what I or anyother ppl said and then u might get higher rateings. 

BlueAlex75 about Crazy Penguin Catapult 2