Well that was an experience. :D Very creative, very creepy, a lot of me saying "what the heeeell...". I very much dug the atmosphere and the waning light was thoroughly dread-inducing, as was the weird grumbling that would occur as you went lower. Definitely A+ for atmosphere. The Recoil Jump was a fun mechanic to get used to as well, it was much smoother than I expected it to be when I first got it.

Some general feedback:

- The checkpoint noise was pretty intolerable. I kinda didn't want to go to checkpoints and ended up turning my volume down because of it.

- The gun reloading / fire rate felt inconsistent. At times I could unload an entire magazine in rapid succession whereas other times there was a bit of a delay. It kind of made fighting the enemies unpredictable and a bit annoying as I just found myself firing while running backwards as they chased me and not knowing when my next shot would go off.

- The Recoil Jump was cool, but when I first got it didn't work for the longest time, it would just make the screen shake. I finally ducked and it made the little ability icon appear next to my  ammo count, but I was pretty confused for awhile there.

- Finally an odd one, at first my character wasn't turning when they'd move to the left, they just sort of backed up, but at some time during my playthrough they started turning properly. I'm not sure what happened but figured it's a small bug worth reporting.

I kinda flew off the edge of the map and there wasn't a reset option so I haven't beaten the game yet, but I'm going to go back in later and finish what I started. Exploring the map was quite fun and as bardycreepio mentioned below the level guides you fairly well despite getting darker and darker. Very nicely done.

I liked how the level "gently pushed" me towards the next skill by leaving me no other option, while at the same time making me search for the way. This is very good level design.

The darkness and the sewer-underground-like setting match very well, and combining the enemies chasing you in the dark gave for challenging moments.

I didn't understand that much how the rebirth matched gaining skills, but the animations for grabbing them are amazing.

Found the gameplay and concept quite fun! I did make it outside of the map 1 time thinking it was a way to go after getting the recoil shot. Really enjoyed it and no jumping was a interesting take . 

It took me a bit to figure out how to recoil jump, but felt nice once I got it worked out. Nice Job will def try and beat it again. cause i missed some things my first go through it feels like.

This is an interesting game and the dark environment was visually very interesting. However, when I got the recoil jump, I realized that I couldn't see where I was trying to jump to. I wonder if setting the recoil preview to the down press of a button to invert the direction of the light from the retical and then release the same button to finish the jump and reset the light could work.

Ok. So the initial SFX was really harsh that "discover" something one. I couldn't really understand what everything was, and the red marker blinked on a lot of things I wasn't supposed to shoot. Other than that the concept was interesting and movement and controllers were alright. Looks like Dan said a lot of the things I was hoping to say. So yea that's about what I feel here.

The idea of no jumping is really interesting concept and I feel it was implemented fairly well. I can tell what you wanted to achieve with this game, but I do think there are a couple things I want to point out.

• I don't see how the theme comes into play other than I die in one hit. If that was the intention, I'm not sure I feel good about that. In general, I personally find 1 hit deaths to be discouraging and unhelpful for the player. I think the player should take at least 3 hits. This gives the player a hit to realize they're going to have to be a little more careful, think things through, etc and 2 more attempts to get it right.
• I can tell that you wanted this very atmospheric feel to it and dim lightning, but with the rest of the mechanics, I think its causes some issues. Lighting was very critical and I don't mind it being something you have to replenish, but I do think that your enemies need to be more visible. Even with full lighting I couldn't see dangers, which isn't great, especially with 1 hit.
• The reticle for the gun probably should only turn a color if its hitting something interactable. Red for enemies, some friendly color or whatever to highlight that it can interact, but youre not in danger. Also, normally I'm not a fan of the reticles being smoothed in their movement, but it does work for this game, so kudos there.
• I had some issues with the shoot jump mechanic not working all the time which eventually led to me bugging out at some point near the power  up and locking myself into a wall :'(

Overall, I feel like I know what you were aiming to accomplish in this project and it was ambitious and a bit unique, so congrats on going for it! 

Super unique feeling theme - the idea that I can't jump and so every venture deeper is permanent was really interesting especially with the limited light. Dying to spikes felt really frustrating, especially with only having A/D to try and dodge them. 

The sound that is there is ominous, alien and creepy - loved it, but overall it feels a bit empty and lacking.

The title/tutorial wasn't very obvious that that's what it was, I ended up clicking the start button by accident.

If you crouch (S) in the tutorial/title area you can get inside the wall on the right