While I can appreciate the concept of the rotating space rocks hitting multiple times, I think they need some adjusting so that players have enough time to react if they move between turns and hit one of your ships. I saw the ship was hit and already planned to move it, but before I could move it was destroyed. I suppose that it could lead to future efforts to stay further away, but when they first show up, you may not have a good feel for where it will end up on the next turn. I thought I was far enough away, and ended up being just close enough to be hit. It really was that being the start of the turn and not having reacted fast enough to move away. Maybe a limit to how fast they can hit the same ship again, or perhaps a short delay at the start of the turn to give players a chance to select the ship and start moving. It was unpleasant, but at the same time, in battle mode I died so often that I suppose it wasn't that big of a deal. I will keep it in mind for the future.
I'm not sure on Kunai. I was able to find a strategy that worked for me. The cost reduction was nice, and allowed using abilities sooner. It was nice to start by giving 1 energy to self and an ally, allowing a setup for the next turn. The special allowing the others to have that was good for longer boss fights, especially for Arcania reducing the cost to revive. The higher speed, but narrow aiming window took a bit to get used to, and was not a favorite, so I did not do a lot of attacks. As it progressed I got better, but for something like the Grapple, I always got close. I'll need to try a play of Battle Mode using different combos of ships, but I am liking the new ones.
Battle mode is certainly tough. It is meant to be a challenge. When I think of a Roguelite, I think of getting more permanent upgrades. With the between battle upgrades being lost when you die, and some fights being hard to survive early on, I think it makes many upgrades feel less rewarding. I'd just get this cool upgrade, and then be in a fight that has 2 ships destroyed quickly. To keep the upgrades survival is important. I think the shield has become almost a requirement. Allowing the specials to reset will help with being able to use the more powerful shield, but even the lesser one can be enough to take an otherwise fatal hit. If you get enough HP upgrades to be able to survive, it makes the others last long enough to be enjoyed. I need to try some new strategies when I next play. Fixing some of the bugs, especially the Max HP up not working, will also help it feel more reasonable. It certainly needs some adjusting, but I'd say that it is tough to define how best to do so until the next batch of planned updates and fixes are in.
I'm not really sure of similar games. You've got the cards and limited slots, but in many ways that could be compared to having equipment and weapon/ability slots for them. Abilities often need something to use. Having a low max, and regaining some each turn is not that common that I can think of, but there are games where you are fairly limited on what you can do and have to build up for more powerful actions. I'll try to think on it more and browse my games collection to see if anything stands out. I've not been playing many non-jam games in a while, so there may be some I'm just forgetting.