Hi! A couple of tweaks I think you could implement:
1- Map the same command to different buttons, like change weapon to both L1 and R1 and stay to L2 and R2.
2- You're probably still balancing the difficult, but the second stage is too easy. Climb the place makes no need for quick reactions since there's no enemies comming from outside the screen. Maybe you could place some enemies comming from bellow sometimes.