Space Invadors

I added to my project picked up objects for power up( incresing speed of firing) also I changed some design detailes and added flying asteroids and gravity which make game more complicated and difficult to win but possible (I checked it by myself :)).

I can't make an main menu button works in instruction page and would be very glad, if anyone should explain me how to fix it. It will be easy just to delete instruction page, but I want to learn :)