Wow! Thank you for taking the time to give such thorough feedback, it's a real pleasure to read through and analyse. I'm so pleased that you liked the game! It isn't perfect, but we are really quite proud of it :)
As far as your gripes, I feel they are most definitely justified.
The map, to start off, is certainly a labyrinth. I had hoped to signpost things better, but this ended up not getting done in time. I hadn't considered the coloured corridors idea though, which is a very good one! I had a thought on the final day (much to late to implement) whereby the player holding the spacebar would bring up an map view of the ship/floor they were on. Also, going waaaaaay back to the planning stage, the rooms were supposedly going to be rather different - a mess hall, dorms and other rooms with various functions and visual differences. This would prove, of course, optimistic. As such, the level we are left with is undeniably obtuse :/ But hey, we live and learn.
As for the ammo, we always wanted the player to feel like they were in danger of running short. The hope being to encourage greater caution and levels of terror. Though, from reading your comment just now, it may not have been clear enough during play that the alien can be evaded if you can break line of sight for long enough and stay quiet. We took a lot of inspiration from alien isolation when making this game (natually!), but never got so far as to add a noise/distraction device into the game - though looking at it now that would have been perfect...
Thanks again for your comment - it's been a highlight of my day! I'll be sure to check out your submission when I have some time :)