ME 1 is enjoyable despite its many faults.
It tries to do many things, and fails at most.
The shooting is clunky, the cover mechanic sometimes feels suddenly forgotten (in some places there's no viable cover despite the game basically requiring it - you could argue this adds realism but it honestly feels more like oversight).
Or the cover is there but the UI glitches and you just CAN'T crouch under it.
Enemies sometimes get stuck under a box or something and do nothing.
The RPG elements are barebones, you can only play as Shepard after all.
The inventory couldn't have been messier if they tried.
The balance is all over the place.
The Mako sections can be infuriating and often the planets just feel empty.
Then again, sometimes you realize, they would feel exactly like that. They are planets, massive chunks of rocks and chemicals, as the database entries explain for each of them.
Every little portion of this game, even with its flaws, adds a little something to the whole.
As I said before, the atmosphere is absolutely nailed - and no, sorry, I won't just go listen to the score tracks on youtube. It's a great score, but it's linked to the game and its aesthetics. That's where it works.
I'm playing a modded Legendary Edition and all in all it's pleasant to visit those places again.
ME 2 has vastly superior gameplay (I had a lot of fun with that one, to be totally honest), so I don't mind too much if other aspects go a bit on the background.
In ME 1 you get in the mood, and in ME 2 you float things and shoot them.