I have the game, and I had the same problem on my Evo 3D. It's not that it won't let you switch, but the screen isn't displaying properly, so you can't see where you're supposed to touch to switch. I managed to find the right spots to tap to get to the factor and bomber stages, but it was a big pain. I've finished the game and uninstalled it, so I can't check to be sure, but I think I had to tap around the level 2 button to get to the next screen.
I wish I had a better explanation for you, but tap around and you should get lucky.