Ah! Thank you for your compliments so much! It makes me feel very warm and fuzzy haha. I did a very poor job of explaining the enemies in-game, and I gave an explanation to someone else which I will paste here:
"On the enemy front, I may have forgotten to imply the noise mechanic further - enemies are a lot slower than you, do less damage and spawn less on lower difficulty levels (but you gain more materials) and won't even pursue you if you're outside of their range (plus a few types despawn all other enemies) so to balance this there's a noise system; some enemy types can hear when you run or drop items, which is what the megaphone icon means. I apologise, I should've explained that further."
I did want to implement a proper tutorial, and had full intentions to, but I had a family member die halfway through development, and thus was stuck for time. I apologise.
Oh, and I should mention - there is a type of enemy that won't hunt down the player, but will infect certain dispensers, meaning if the player is near them for too long they will die. I'm sorry, I did a very bad job on the tutorial haha.
Thank you so much regardless for playing my game! I really appreciate it.