This is an excellent entry, as you're well aware. Good work. A full, playable game with original art and music. Quality stuff. You've already got a lot of great feedback so I'll try to focus on things others haven't mentioned: 

1. There's no autosave after you beat the final boss; During the escape sequence I missed a jump, ended up in an entirely different area, and had no way of getting to where I needed to be except backtracking all the way around. Before I got there I died and found myself having to face the final boss again. Aaaaaaaaaaaaaaaaa. Maybe I'll try again later, but I don't know... 

2. I *really* wish saving would refill health, at least before the final boss. I found myself going in with 50 health and no vials in sight. The final boss was pretty good--challenging and intense--once I realized how it worked. But it was way harder than I anticipated bc of the save issue and because I foolishly did not get enough bomb upgrades. 

3. I quit this game and picked it up again several times because I kept getting stuck. For me, the environmental instructions were a little too subtle. It began with the first boss after getting bombs. The bomb targets didn't really look like targets, and even though I blew up one, nothing happened. It didn't occur to me that I needed to find and blow up all of the targets in the area to get out of the room. I thought it was soft-locked. This happened again after getting the whip. There was so much going on in that chaotic miniboss room I had no idea that I just had to keep whipping the thing over and over again and causing the miniboss to keep getting zapped. And again I was confused with the final boss, though by now I had kind of figured out how the world worked and figured it out without too much trouble. I think one thing that would help would be showing the player a more immediate connection between cause and effect in simple rooms, and be a little more obvious with player feedback.

4. I think at times the level design did not live up to the potential of the mechanics. Large sections of the game felt like "homework" jobs, like 1. collect bombs, 2. bomb targets, repeat. Some of that is not bad, but at times it felt a little tedious. 

5. I like the aesthetics a lot but it could use some variety.

Overall I think it's a quality game, definitely one of the best entries, and I hope that some of the issues people have raised get addressed, because it's nearly there. 

Solid game! Nice clean art, fun story. I especially liked the inclusion of an escape sequence, made me very happy lol.

There were a few of points in the game that I was confused by...
* The eye boss in its entirety is very unclear, I think I might have spoiled myself a bit on it by glancing at the comments, otherwise I might not even have tried to hit the main eye or realized I was in a boss room at all. Hitting sewers until they were deslimed in order to wake up smaller eyes that shot at me so I could hit a bigger eye that would teleport me back up to where I started where I had to whip one of the battery obstacles... everything felt very arbitrary and it wasn't until 4 or 5 deaths in I felt like I had a grasp of everything that was going on there mechanically. Not sure if I just didn't pay enough attention to the lore or what...
I think one of the smallest ways to remedy it might be decreasing the size of the arena (at first?) so that the player sees the main eye waking up, since when you enter the arena it does nothing and you can't interact with it. I also somehow didn't realize the small eyes straight away, they felt like they come on randomly, especially I think because they come on after one hit while the sewer takes multiple hits to set off.

I will say though, once I grasped everything it was a very fun challenge to dodge everything while running everywhere, although by the sixth battery you do start to feel exhausted lol, and there doesn't seem to be a way to heal once you run out of vials since they don't respawn.

* Spikes were incredibly confusing. At first, I got jerked around by purple spikes, and just assumed I had stepped on an unrelated teleporter. Later my conclusion warped into "oh, I must have died, and it started me back at a checkpoint", but sometimes that checkpoint was further ahead of where I was when I had stepped on the spike. I didn't even realize that I hadn't truly experienced death until the boss fight.
Maybe some kind of particle animation that moves you back to start would make things less disorienting?

* Red spikes as well, they drain your health over time, but there's not really any feedback saying 'ouch ouch ouch I need to get out', so it could be red grass for all you know until suddenly you're dead.

The music in the escape sequence seemed a bit... chill? Not sure if that was intentional since it did cut off in the beginning

I'm also really curious on to the decision of making bombs limited, there were quite a few times especially early on where I ran out of bombs trying to hit switches and awkwardly had to run back to somewhere I knew refills were. Even in the case of combat, none of the enemies are threatening enough that I'm in danger of overextending by using them, since I can just lob a few, run back a bit to refill, and then return. The one exception might be the boss, which certainly is painful if you waste bombs on anything but the main eye, but I'm not sure it needs a difficulty spike on top of the many constant lasers lol.

Bombs are also probably the most fun thing in the game to use, the first thing you want to do when you get them is go nuts and throw them everywhere!

I also thought having the doors set up the way they were was interesting, it's pretty uncommon to be able to close doors. You might be able to create instances where the player is desperately running away from an enemy, and has to close it to keep it out? Just a random thought.

Overall it was a fun experience! I don't think I ever got too lost despite the map feeling quite large, and I really liked a lot of the smaller challenges like the moving platform on-rail challenges and the escape sequence. I'd say things like that gave it a really nice variety in the gameplay that I haven't seen in this jam.

Great metroidvania! Simple yet appealing graphics and good animations. The controls worked and the puzzles along with other level design were done well. Love the death screen lol.

Things I think should be fixed or improved:

-The enemies can damage you while dying.

-Attacking interrupts your jump and resets the gravity.

-There wasn't any music playing at the upper section.

-You don't start with full health after death.

-While the final boss fight was very interesting, it was too obscure and difficult for its own good. The attacks weren't telegraphed, there were a lot of projectiles and the character had no invincibility time so dying was very easy. I kinda have a love-hate relationship with it.

While I have some complaints I still enjoyed my time!

I ABSOLUTELY love this game.... it's really nicely designed got great atmosphere/graphics that perfectly fit the mood, a lot of backtracking  with great opening up of the areas once you have new abilities. Not finished yet, but fully intend to come back to this one, and get past those silly blue eyebally things firing all their rays at me!

The negatives are all very minor, but minor annoyances were that - the jumping initially felt like it could be a little more responsive/use some coyote time, but I noticed it less, and less... the floaty enemies got stuck and their hit boxes to do you damage felt a bit bigger than was intuitive (but again I noticed this less and less playing the game).. Also I found myself in the bulkhead area teleported to the low exit area on getting injured (think this is a bug rather than I accidentally hit some form of intentional teleport I didn't notice?). A little more feed back (say an unlocking whirl or other indication when you unlock the doors, might help a tiny bit, to know when you are done with an area... However none of this detracted from my overall enjoyment (as I mentioned, I really REALLY loved this game) 

Great Job!

Really nice game. The aesthetic is consistent and the music matches the mood. I thought the level design was decent. The movement feels crisp and fluid, and I think you got the jump juuuust right.

I could see spending a substantial amount of time on this game, great work!
 

Very enjoyable experience! The atmosphere feels very lonely and desolate.  Simple and effective.  The controls felt a little unintuitive to me on KB+M, but can't comment on how it feels for controller.  Nice work!

Level design became better, but I got softlocked anyway. Controls feel solid, graphics are good. The game was a bit boring at times though, but it is by no means bad.

Loved it, felt smooth and satisfying overall and definitely fits the genre. The minimalistic soundtrack compliments the environment really well, and the whole game feels well thought-out. The animation for the pipe swing in particular felt really nice for me :)

Very intriguing! I got stuck in the room with the six cells in the low exit, above the weird eye boss. I activated all six cells, went to fight the eye thing, it zapped me, and sent me back to the six cell room, with one destroyed. All doors were sealed and I couldn't do anything else.

I got stuck in a place with a "low exit" sign... but that's probably just me.

Other than that, nice crisp pixel art and a quite elaborate level design. I enjoyed playing this one!

I looks and plays very nicely! I kind of got stuck after finding the thingy after you jump over a bunch of spikes. I liked the relaxed tone and athmosphere (and the music)! My constructive feedback would be that the relatively empty rooms and slow movement speed make it a bit hard to stay motivated to search for the next place to go.

i like the level design in this a lot! reminiscent of metroid 1. the art style is also very nice :)

i didn't get very far, because my progress wasn't saved (idk if this game has saving, but i was in private-mode by mistake, oops), but the combat seemed a little bit samey.

regardless,  very nice for having only a month to make a game! ^^