I recorded some short video of me trying out your game

https://litter.catbox.moe/grzls3.mp4

It's the older linux version, no commentary. Watch/download before the link expires.

The video must look really weird with no commentary. Like I am doing some weird things. The reason for that is because for some reason the game would sometimes ignore my input, and make my character stop. I do not know if it's linux specific bug, weird velocity resetting, or maybe you are reading input in fixed update instead of an update, but it made it really hard to play.

I am sorry I did not ply for longer. I tried to figure out when I had problems with input for the most part.

Definitely preferred it with gravity. Zero gravity with no momentum feels off, and adding momentum would make precise movement impossible. I also have the hunch that having gravity allows for more interesting and varied level design. Or you could just do both and have some levels with gravity and some without.

I think this game shines best when it treats the different subweapons as pieces to solve a puzzle. I enjoyed the rooms styled around the laser or the axe and figuring out the safest way to progress through the different spawns with the least danger.

I would actually second your idea you had below to completely cut the gravity, I kinda thought the same while playing, I feel you could have a lot more dense bullet patterns and precise dodging if you don't have any drag or gravity, etc. Although that would change the genre almost, but I could see some bullet hell/castlevania crossup working. Either way, this had a lot of cool moments and a good feel to it, good job!

-Candles make no sense for a sci-fi setting, and weren't a very good mechanic in Castlevania in the first place.

-I don't understand why there are "pets" hidden inside the candles or why they're used as currency.

-Juding by the videos you posted, it looked like it had the worst jumping physics imaginable. You really need a particle effect to make it clear that you have a jetpack.

-Make the flight time limited (but still generous) and have it recharge while on the ground to give the player a reason to not stay in the air all the time.

-When on the ground, the character should jump before activating the jetpack, and you should be able to jump without using the jetpack by tapping up.

-Gravity stops working when you fly into walls.

-You should be able to shoot crates to open them.

-Don't hide enemies in crates.

-Hits don't register if the muzzle is less than 3 pixels away from a target.

-I hate the short range on the gun. Feels really unsatisfying.

-The axe feels almost mandatory. It's pretty much a game over if you lose it. Laser needs to go through walls.

-Spawners are too fast for how cramped the levels are. 

-Needs continues, especially for testing.

I can kinda see what's being gone for here, but personally I did not enjoy it much. It might have been largely because the controls felt sluggish, and I was unable to keep up with the constant enemy spawning onslaught in an effective manner. Maybe there were some controls I missed. I do not know.

This game feels extremely weird to play at first, but like Rokas said, once you get it it's okay, still feels a bit weird though, something about the low gravity pulling you down while you can freely move in eight directions and that heavy recoil. I think it could do with some momentum, but I'm biased in that I generally hate momentumless platformers.

I didn't quite get what the yellow candles even do for me. Also Pets are the robots walking around, and they're currency? This is all a bit confusing.

Enemies feel extremely basic but they work for what this is, feels good to finally chase down a spawner and get some peace from the enemies it spawned.

The Linux version works fine btw, although only the left sick worked for movement, not the d-pad.

- zip the game folder, not the files (correct: Game.zip/Game/Game.exe, wrong: Game.zip/Game.exe)
- since mouse does no aiming, add a keyboard button to shoot with (F/Space)
- custom engine vibes, rare in a unity game
- does the game end? got to level 3 (4?), where there's 3 turrets in a vertical tunnel and 3 falling books, when I try going right, the camera doesn't pan, but there's things shooting from there

Started off feeling pretty jank and I was about to start nitpicking, but then the mechanics clicked and it felt pretty good. Smooth and responsive movement + hard enough to feel challenging and encourage getting good. Struck a good balance on the spawners, where you have to both clear the spawns or get swarmed and do it fast enough to get hits in against them. I generally despise platformers/metroidvanias because of how tedious and braindead they are, but this got me engaged. Did not expect much going in based on the screens, but the sharp mechanics won me over fast.  Extremely tense on 1hp, I love it. Good game, thanks for making it.

I haven't played much of either Castlevania or Metroid but this didn't really feel similar to those at all. Other than getting weapons and ammo from candles. But maybe my expectations were just wrong. I found most combat encounters mostly annoying to fight, mostly because of the standard spawner enemies I think. I don't think there's a way to see your equipped subweapon, that would be good. The strafing mechanic is pretty weird. I think I'd prefer it if you could shoot towards the direction of your mouse cursor instead, either left or right that is. I quit after dying right after the "boss" and having to restart from before the first shop. Enemies can follow you through screens, I don't know if thats intended or not.

Shooting having knockback is neat. The Screen not aligning properly during movement of that knockback, causing it to kind of mimic screenshake but in a bad way isn't. And if its actually ment to be screenshake, not on shooting the Autoattack, it feels odd, especially if its constantly. If getting hit by something maybe, but not like that.

I don't really have a jump, but can just float wherever I want with W/S, but with some super light gravity applied? I'm assuming its to mimic a jumppack or something, but it'd trivialize pretty much every movement option in the entire Game if I'm starting with that. So you can't build a lot of interesting passageways to block off early for that castlevania/metroid like progression. Also it feels floaty and boring. 

And even on PC controls I shoot in the direction i'm facing, not the one the mouse is? If so, get rid of the mousecursor, and mousecontrols entirely, and have classic Gamepad controls of WASD IJKL or something like that. with Jumping on the extra buttons, not on WASD, so you can use W to change stance or something, and s to crouch. 

Took a bit to figure out I could shoot the red and yellow things. I now have 5 Es whatever that means, and 4 Pets, after shooting the first ones a few Times. Why can I even shoot the Pets if its currency or whatever? And what kind of currency is a pet? Strafing slows you down way to much, its easier and better to just float around the enemy or whatever.

Gave up on the Screen with 3 Spawners shooting bullets at you, thats just ridiculous.

Theres nothing Castlevania or Metroid or anything like that going on, its just a platformer without platforming and a rather bad shooting Mechanic. I just floated through the levels trying to aim my shots up with the spawners so I could float into the exit and load the next level.