Hi! I totally understand the struggle - the game is much easier with a mouse, if you’re currently playing on trackpad. (Once I swapped from trackpad to mouse I beat it on my first attempt, in under 5 minutes!)
The way the enemies work is that they approach you and fire once they spot you, but they’ll stop firing if their line of sight is broken for a few seconds - hide behind a building and they’ll turn away & continue roaming. (The rocks currently don’t have collision, which will likely be patched after the jam!) They also die in one hit, but I believe the player’s firing range may be a bit shorter than the enemies, so I do agree it’s hard to tell when you’re getting hits in! We did plan for the enemies to flash red when hit & then disappear in a puff of smoke, but we sadly didb’t have time to implement it. There also is a final boss that shows up when you defeat a certain number of enemies, although I don’t know exactly what the number is.
Overall, this is all really helpful criticism for how to continue to move forward with this game and / or future projects, so thank you so so much for the feedback!! :D