Two ways through the same three stages.
Move the mouse to fly — the ship goes where the cursor is
Drag anywhere to fly — the ship follows your finger, offset so you can see it
Firing is automatic
Right-click or X or Shift bomb P pause M mute
Tap ✦ or a second finger anywhere — bomb
C chain lightning — one a stage, clears the screen and chains through every enemy
Tap ↯ — chain lightning, one a stage, clears the screen and chains through every enemy
Arrows or tap to choose — Enter to continue.