It's a pretty good metroidvania.
I've had a good time but a few things could be improved.
First is the X swing, way too powerful against everything that is grounded and has rendered a few bosses a joke. Sure the boss that guards it is super tricky to defeat, but that was until I found the right wall and used that to have enough room to react to the boss passing through.
Second is the way the powerup selection is done, I'd rather you make it more like super metroid, where one button selects and another activates, it could even have them start when the button is pressed removing their start delay.
Third is the general directionless after getting dash, if I hadn't committed to memory the 3x2 room in sector 2 that screamed to me that it was a boss room prior to getting dash, I'd be in more trouble. You get an initial marker the first time you visit each sector, but after that it's pure guess which box could contain the next boss. Specially since I've already been to every corner of sector 3 prior to getting dash.
Doesn't help the one scientist helping you gets done in when you get dash. So navigation rooms just become decor then.
Bugs:
Gun sometimes gets looping the reload bar while at full ammo, will cause a reload to happen when it completes the rectangle and the player has depleted some ammo.
Sector changed states don't seem to like to stick, entering some rooms causes those sectors to revert to their original state. Sector 2 reverted to its original state after defeating the boss in lava. Same for sector 4. Unsure if defeating them was intended, I'm sure it reverting when some rooms are entered is unintended.
Problem I've had is I've seem to have sequence broken the game by getting X swing prior to getting dash. There might be one boss left in sector 3 as that's the one sector that isn't changing back on its own. I'll comment again if I do find a solution or if I do give up.
Update: there was a boss remaining in sector 3 and after that I was given the upgrade for generators upon returning to the hub.
The unintended thing here seems to be Nano Shield completely protecting the player from lava damage even after it's depleted. That's what allowed me to just waddle through lava with little to no consequence.
Update 2: beat the game, cheese all around, after dying several times to the final boss I managed to do a simple loop with nano shield up and defeated it without taking damage. That boss having an instakill that bypasses invincibility was annoying and it even activated that while it was on its death animation on the previous attempt.
I'm sorry for busting up the intended order of the bosses, the challenge was all messed up because of it.