You win the game by defeating the final boss.
You lose the game when all your energy on the top left is depleted.
You gain energy by collecting coins and rings.
You lose energy when you get hit, move or shoot.
for computer players:
Use the wasd keys to move.
Use the J key to shoot.
Use the K key to fully heal, if you have 3 rings collected.
for mobile players:
Drag the ship to move.
Hold the ship to shoot.
Tap on the rings at the top left to heal, if you have 3 rings collected.