Suggestions from me which I think could improve the game:
1. Ship choices: A selection of multiple ship varieties to choose from at the beginning and a possibility to name your ship (personalizes the game).
For example:
°A standard ship with a solid average in each stat
°A tougher ship with low range but a superior damage output, a shorter light range but 270° light angle
°A long-range ship with a longer but narrower light cone and less damage tolerance
Maybe you could also think of one or more further ship types as AoG exclusive or AoG supporter exclusive choices

A fast-moving, repeating fire ship for example.
2. Controls:
°Give a selection of control choices maybe or simplify the controls. For example, mouse only with mouse click=move/attack and mouse cursor=facing. Or keyboard control with the cursor key and space for fire. Maybe you could give the option to alternate between the two.
°Zoom option: Didn't see one, but an option to zoom in and out would be helpful I think
°In-game mini-map: A small map where you can see where you've already been somewhere in the corner, maybe to be opened with a simple key stroke ("m"?)
3. Upgrades: Upgrades are a little bit intransparent. Maybe you have already some of these. If not, consider them:
°improvable freight space for equipment found
°specific slots to built in found equipment (e.g. shield, weapon, lamps, engines, armor...)
°basic upgrades on a point-buy basis (damage, speed, light range,
light angle (!!!), weapon range, hit points etc.)
°Achievements: Provide achievements, which give bonusses. For example, offering an unique piece of equipment for each achievement won.
°Trade: Could you think of a way to "sell and buy" found equipment? Automated converter posts maybe? Or simply unexplained between levels?
4. Level design: Due to my inabilty to handle the controls I didn't come past Level 1 so far. What I would expect:
°Landscape design: Create not only cave systems interconnected with narrow tunnels. Be more creative. Make some open ranges dotted with a few obstacles or recurring elements, tunnel-only systems, a web of large caves, artificial chamber grids etc.
A change in color and texture design would also help.
°Interactive elements: Switches that open barriers, energy posts that open barriers when destroyed, moveable elements, switches that open barriers when held (e.g. by pushing moveable elements onto them), destructible barriers, barriers that cannot be crossed but shot over, reflective walls (ouch! - but would also reflect light and increase your sight radius). These would make the levels more interesting and maybe add some minor puzzle elements.
5. Enemy design:
°Work it out clearer from the background story what exactly it is that makes the "bad guys" so bad.
°Create different types of enemies. Examples for the beginning:
-A standard ranged attack enemy that can however only attack if standing still
-A tough close combat enemy that will try to ram or bash you for severe damage, but has to come close to you
-Fast moving little bastards, hard to hit, but need lights themselves and thus are easy to see from afar.
°Use the opera-glass-effect: You could do so by providing a "badguypedia" where the player can see an enlarged picture of each enemy already encountered and a short description, containing "story information" (merely for background and entertainment reasons) and a description of its strength and weaknesses.
(Spaceship selection, as described above, would also provide an opera-glass effect for the player's own avatar.)
°"Badguypedia" could also contain a kill count for each "bad guy". Reaching a specific kill count could earn an achievement.