I'm playing JJ1 right now and honestly finding it a bit difficult.

One of the things that tend to get me the most is when enemies shoot at me from "outside" the screen, i.e. I can't see them but they shoot at me still. On the other hand when I shoot at them, my projectiles seem to disappear just as they hit the screen frame.

Is this the way it's supposed to be or is it some weird compatibility issue?

That may just be raw terrible lead distance. Are you playing just DOS or a source port?

Uhhh, not entirely sure but I think just DOS? I just downloaded whatever Gog provides and run that.

Yeah, just plain DOS. Which as I mentioned, the lead distance of the zoomed view is a common complaint.

Right, got it! Thanks for the explanation :)