The white bullets on a white background of large clouds in level 1 are invisible.
Keep the background, which is quite good, and redesign the bullets (either a dark center or a dark outline would provide the necessary contrast).
Weapons that need tightly timed double or triple tapping to operate are very slow and frustratingly difficult and unreliable to use.
Instead, they might charge up without player action and shoot instantly, one with a single tap (the column laser would be particularly suitable) and the other automatically when a large target is acquired, or there are many enemies on screen, or the player taps the screen with another finger, etc. (the method could differentiate the weapons)
Thanks for your valuable opinion ! I will consider of your suggestion to see can change if any. Currently I am constructing the 2 play online mode and may release later. Thanks !