Your fighter fires automatically — just steer: move the mouse, drag on a touch screen, or use the arrow keys / WASD. Shoot down enemy squadrons and grab drops: P upgrades your guns (up to level 5), W calls two wingmen with missiles, a heart restores health and a bomb refills your BOMB (B or X key, or the bomb button) which wipes every enemy bullet off the screen. Every seventh wave a giant bomber attacks: destroy its four turrets, then the cockpit. Getting hit costs a heart and one weapon level.
Tougher squadrons, denser bullets, fewer hearts. Play Sky Squadron: Ace free in your browser — no download, no sign-up, on phone or computer.