Fonzer: Actually played a little doom 1 enhanced and it works fine for me on my laptop.
I don't think i need to kill all the enemies and find all the secrets in this game.
And certainly not getting all the pickups since i am new to this game.
You don't need, indeed. And in later levels things can go pretty big and difficult and probably your main interest will be stay alive.
But in later replays (I do not know the number of times I replayed those games across the years) you will notice that find the secrets etc is half of the fun, specialy when you are familiar with the maps.
greetings