This was pretty cool, I loved how the game centers around the use of the flashlight and its batteries. Needing it for being able to navigate, open doors and fend off enemies makes you mindful not only of how many enemies there are, but how far you've gone into a level. The loss of battery power on death magnified the importance quite nicely as well, I think you nailed making large parts of the game center around simple mechanics.
The visuals are simple but nice, I think it works especially well for not being able to tell exactly what the enemies are. The music fit the game quite nicely.
Also I do appreciate the little collision indicator when running up against an invisible wall, a very nice simple touch.
The game was a bit confusing at first as I wasn't sure what I was supposed to do. The first time I got the little black ball to feed the void, I assumed I had to collect more of them in the level rather than bring it back to the void. I didn't read the games actual page before starting, so that may very well be on me.
One bug I encountered was after having died with no battery left, I was respawned back at the start with a full battery. From reading the devlog it seems like the player goes back up one level if they die without any batter left (?), can't confirm as I stopped after I died on the third level. But even though I had the full battery, I was unable to use the flashlight, and so got softlocked. Exiting back to the menu and starting a new game fixed this, and since I was at the start anyways it wasn't too bad. It might be an issue in further levels though.
Also I agree with Not Jam's suggestion of a minimap of some sort, the third level for me was starting to get a bit big for navigating by memory. But you already mentioned it being included in the next build so I imagine this will be fixed soon enough.
For the feedback questions:
- It was easy to defend against enemies, the times I died it was because I either ran out of batteries or I forgot to check with my flashlight if the room was clear.
- The controls feel responsive enough, I don't have any specific suggestions or complaints either way.
Overall I think you just need to focus on a couple quality of life features like the minimap, a bit more of an in-game tutorial, and you're good. Great work!