Your game was advertising for its heavy Risk = Reward -based system and I got what I wanted. Will wait for the full release.
Some feedback now:
Gameplay
Great value system. Grazing offers direct gameplay reward, not just score. Losing 1 health chunk per hit but requiring 9 health points (from destruction loot) to recover a chunk makes taking damage critical. It also matches the pacing of a game where you destroy 90% of the time and get hit 10% of the time.
I'm still not sure what to do if my Barrier Breaker gauge is full but I'm not in direct danger. Usually I would keep it for later, but maybe there's a bonus score if you destroy even simple units with the Barrier Breaker.
I hadn't noticed that Barrel rolls increased fire rate (as mentioned in a comment), but I guessed it increased grazing reward because it fits Risk = Reward. I'll play again with more rolling but I fear I'll end up spamming them up and down for some extra fire on a precise target.
UI
Simple controls, the keyboard default has a nice symmetrical feel.
As mentioned in other comments, some common gamepads don't work so I won't say more on this.
Keyboard works fine and is enough for a game that doesn't require aiming at given angles. However, the keyboard configuration screen is hard to use: it is a bit old-school and forces you to pick all the keys for each action in order instead of letting you choose them freely. But more importantly, it doesn't let you leave the screen until you're done (Escape input is captured, but ignored as it is an invalid input, so it does nothing). You should always be able to leave a config operation in the middle and cancel it.
FX
Epileptic effects in both the menu and in-game are still a problem. The warning at the beginning is the minimum but the problem remains (for legal reasons even games with not so hardcore FX end up with the warning, so when I see one in a game I tend to ignore it thinking it won't be that terrible).
I would say that unless you have a very good reason based on art direction and world immersion, you should avoid epileptic effects at all cost, and even when using them add an option to deactivate them. For non-epileptic but disorientating effects, a toggle option would be enough (unless it's VR).
Here are 2 examples:
- In a movie, a dysfunctional neon in an abandoned shop that switches on and off gives a sense of uncertainty and incomfort. The character may be attacked from the dark or find a corpse. Removing the neon would diminish the experience a lot. The scene is still short, and the neon switches from times to times, not at high frequency. OK. Watchtest with different people if you're unsure.
- In The Last Story (Wii), the camera rolls when inside a sailing boat (immersion), but it can be deactivated in the settings (to avoid motions sickness, or just for gamers who like things straight).
In your case, most effects are not critical for the experience.
- The faces in the radio dialogues don't need to glitch unless you want to mean there are interferences.
- Menus may glitch a little for aesthetical effects, but the current on/off at high frequency effect doesn't make the menu more beautiful or immersive. It you want to evoke CRT, old OSes or mil
- Muzzle flash is a bit tricky because it's a diegetic effect. Personally I wasn't disturbed by in-game effects so much, probably because I'm expecting them in a shooter, I'm focused on my ship and FX help me identify potential threats quickly. So flashy effects have a gameplay and aesthetical purpose. But you can still playtest with a variety of people to see what's fit and what's not. You can also compare to other shooters to see how they manage to show muzzle flashes without being epileptic (like showing a sticky flash, blending, etc.).
Also, remember that adding those effects cost you a little each time. Removing them in the end will be cheap, but you would have lost the initial time spent on them, so design them wisely from the start, or start with basic effects leave the details to the polishing phase. You wouldn't want to make great gameplay inaccessible to some people because you put the wrong FX.