I played something near 4 hours, i didn't finish the game yet. I made it as far as level 5, but i'm a little tired right now and i getting worse and worse with each try. So, time to drop some random feeling i had on the game. To be honest, i liked most of it. I liked the pace, and i felt the game was overall fair, so i don't have many things to say. I just have the habit to go into wall of text every times i have something to say. Oh, and sorry for the grammar, i'm not a great english writer.
Offensive stuff : Like many games, i favor offensive stuff, just because it make many encounter easier, just because you have to dodge for a shorter duration, it's especially usefull against boss, who are often static with hard shot pattern. Anyway, i never felt like being over-powered. Even with the best stuff i found, i could'nt just jump in and kill everything, because you die quickly, and in many room it's hard to simply reach a line of sight without taking some bullets. But for some room, the game is stil made far easier with some good gun upgrade. Like that boss Paragon, which is a pain for me to confront. You can just kill him before he shot any seeking-bullet, or in some of the most open room where you can just blast your way using your two shield to protect you. Overall, i had powerfull auto-hit in most of my best attempts.
Defensive stuff : On the other hand, Defensive stuff is not allways that usefull for me. If you don't have the dammages, boss are long, and you never have enough shields/energy/health to constantly skip dodging. In a way, i find boss to be more forgiving with good dammages than with good defenses. Defensive stuff are best used in room where it's hard to find a line of sight, with a lot of ennemies shooting throught the wall, or against some of the hardest patterns. I also feel like the more cheesy stuff may come with the defensive stuff. The weapon which can stop bullet can be really powerfull with some attack speed, and the ennergy weapon which make a shield seems to be a good way to shoot your way if you can't dodge. But again, i never felt overpowered, and even with the best stuff, you have to adapt to the situation and manage your ressources.
Missiles : I like the way the missile work. It's probably the powerfullest stuff in the game : You can use it to grab a little more stuff, you can stop some bullets with it, you can kill a tanky monster pretty quickly, if you can aim right between is own bullets. It's both skilled and powerfull, and it's a ressource i have fun to manage.
Energy item : They're quite interessing, never felt any was really powerfull, but they can be a nice help, and it's fun to try and find a way to adapt your playstyle so you don't wast the per room munitions. There's also some nice combo to find, and i still wonder what i could do with a lot of energy booster and some protection item, like the shield.
Spacebar item : I did'nt figure out yet how they work. I find them pretty hard to use in usefull way, and i still struggle to understand when they're conssumed and when you can use them multiple times.
Minibosses : I mostly like them, they're usually not this hard, and they're not too rewarding. But i'm surprised how some of them are easy. Trio have a short range, and you just have to outrange him to be safe, hunter is surprising the first time, but now i just circle around the room and he never touch me. On the other side, i still struggle against some boss like Paragon.
Keycards : Like in many "leveled based roguelike", i find them quite frustrating. Sometimes you can't loot any, and you find many locked doors. Sometimes you even see locked door behind locked door, wich is extra frustrating for me. It's a part of the generic random procedural stuff i guess, but i will find pleasant to have the certitude to allways find one keycard somewhere hidden on the level, and no more than three locked doors.
Mines (energy slot item) : I don't find many use for them. Many of the harder ennemies don't move that much (Like Blaze cannon or boss)
Blaze Cannon : Its the most frustrating monster for me. In fact, it's on of the only i really find "unfair", even if he's pretty easy to kill when you get a line of sight, simply because his shot pass trought wall. It make some level very hard, and i find it strange to see the missile just sparkling trought the wall.
Spiders : This ennemi seems pretty worthless to me... The dammaging pattern is slow to deploy, and have a short range.
Wall Master : Yea, sure that boss is more powerfull than most of the other. But i just feel like it's a good time to shot mass missile. Still, he could probably use some less hp..
SwarmLord : I have framerate drop on the second phase of this boss (where violet bullet explode into lot of greenstuff). Not a big matter, but as it slow down the game, it make the fight way easier.
General feelings about ennemies : I like how the fact that generally the most hard and "bouncy" shot patterns are also the slower, so you can see it coming. Most of the difficulties i have come from room with little space to dodge, or labyrinthic room. But i feel it's a needed difficulty so you have to adapt to where you are, and dodging bullets never really become a routine.