Hold the LEFT or RIGHT side of the screen to steer your sinking probe. Sonar pings reveal the walls for a moment - remember them. Jellyfish glow on their own and give bonus score plus a free light burst. Mines barely glow at all. Survive as deep as you can.

WASD or arrow keys to fly. Hold Space to fire. B or Enter drops a bomb. F releases flares and is the sure answer to a missile lock. Shift or E triggers overdrive. P or Escape pauses, and Q stands down. On touch, drag to fly and use the on-screen buttons. Skim close to enemy fire to charge overdrive. Destroy ground targets for upgrades. Only finishing all five stages posts a score to the leaderboard.