I am going to break up my review into several posts each focusing on different things. This first one will be my general thoughts and comments as I play through the game.
The Badges, Abilities, and Tutorials have no BG music. You have such nice music, that it feels oddly quiet when you go to any of these from the menu screen, especially the tutorial. Many people will start with the Tutorial, so may think the main game doesn't have BG music, which could deter some people.
The tutorial looks like it hasn't been updated in a while, and could use some work. I'm pretty sure I mentioned several issues with it in the past, but let me know if you'd like me to share my thoughts again, as I did play through.
When starting the first mission, and the music stops, it feels abrupt. Maybe add a short fade out.
The Press E to skip message is largely covered by the character dialog. It did show before, so players may know about it, but may not have caught it before, or notice that it also applies here. It seems that the in combat dialog cannot be skipped with E.
Having played through before, I'm acknowledging that you don't get to pick your cards for this first fight. That is probably the right choice as players won't know what to pick before getting a fell for the game, and this also gives an idea of how you recommend outfitting each ship.
I found Shotgun to be fairly useful here as the biggest damage dealer. I only had to move about 1/3 of the way across the screen for all 3 projectiles to hit such a big target.
In combat I had the Blast Gun, though did not last long enough to use it. It was also one of my unlocked card after the combat.
After combat you get to outfit your ships. It would be nice if they started with the same loadout as you had in the combat. It is good to encourage players to experiment, but some players may also like to have something to start with and just modify, instead of having to fully pick every card. Many likely did not pay a lot of attention to the initial cards, and some may feel a bit overwhelmed at suddenly trying to pick a full loadout.
I really like the toggle for Card Hover. Being able to them bigger can be nice if you have a smaller screen, but it also can feel a bit laggy and in the way. I don't recall when you added the toggle, and initially I missed/forgot it on this playthrough, but before I finished my first ship's loadout I toggled it and personally prefer this way.
Second Combat:
The enemies' first turn they each used a different card to build up energy for the other, which was an interesting tactic.
Third Combat:
The lower enemy is cover up by the UI and might be initially overlooked by some people. They become clear once you take any action that hides the bottom UI, so it is probably not too big of an issue.
The Crusher
It would be nice if the between battle card select screen listed what battle you are on out of how many. I took a break and when I came back I couldn't remember which battle I was on, until I looked at my notes.
Now that I've swapped out the Blast Gun, this level has smaller enemies close enough together that it might have been more useful, though I forget their HP, so maybe not as much. I'd probably have tried it out if I still had it equipped, but also don't really regret not having it.
I had a Primordial Stone show up. I wasn't sure what it did, and forgot to right click to check it. I hit it in one of my attacks. Not what I was expecting, but the fight wasn't my best work at that point, so starting over wasn't a terrible result. Except that my fuel did not seem to reset, so I was unable to reposition my units that had already used all their fuel that turn. I'm assuming this is a bug, and fuel should also be reset.
For the boss fight I went back to my strategy from previous games of using all the special abilities to open the fight, then hitting with the strongest things I had.
The Phantom
Nothing of note here. Simple, straightforward boss fight.
The Signal
Signal Boss Fight:
Started with Energy Avalanche, but did not do normal combo, as wanted to focus on taking out the healers, rather than main combo on boss. Took out both healers on the first turn, doing some damage to Signal as well. Next turn used Energy Infusion, Laser of Lament, Sheer Gumption, Energy Infusion, Phantom Ray, Doom Pulse, and that ended the fight.