Guessing a lot of people tuned out because I released so many maps in such a short time, with some being a lot more difficult. I tried to cut back on the difficulty later on.

A bit baffled by the low completion rate for this one. It isn't that difficult. No instant death traps. Enough ammo for all enemies. No difficult jumps.

There are also pick-ups not needed for anything.

Did there exist a different earlier version for this map?

Perfect playthrough by Blade Cop: https://youtu.be/VP6KazYEdvc -- check out his YouTube for many more playthroughs of user-made levels, you can learn a lot from his techniques!