v1.0.7: more bugs fixed, re-balanced flak and rocket turrets, ultragun auto-fire toggle ('Z' key), ultragun projectile speed upgrade, checkpoint now saves fighters and drones status.
v1.0.6: various bugs fixed, grammar check.
'A'/'D' or arrows to scroll the view. Left mouse button to shoot, keep pressed to shoot continuously. 'Space' to bring up the upgrades, 'C' to center the view, 'H' to hide the hit-points overlay, 'J' to toggle the HUD. 'Q' to toggle quality, 'M' to mute sounds, 'P' to pause.
There are several turrets available, each with different use (lasers - all round usage, flak - against fighters, rockets - capital and slow fighters). Also, you have fighter bays, fighters are used to distract the enemies.
Drones will repair the ship, so make sure to upgrade those in "Repair Bay". You may also repair individual systems.
The game will auto-save at checkpoints.
Feel free to ask for specific tips. Hope you'll enjoy this game.