I would usually be sad to see another original RPG go 5e compatible but Neuroshima was infamously poorly designed ruleset, possibly worse than Shadowrun. I probably won't be running it, but may steal statblocks for my 5e game if I need weird stuff again.
Shadowrun is a "crunchy" game, this means it has a lot of rules, and those rules are not simple. If everyone actually learns the rules for their characters, and people don't do things that are extremely odd, the game can run smoothly.
IIRC from when I ran it, if someone does a normal melee attack (without any magic, hacking, or vehicle shenanigans), it's like 20 steps, and some people can attack 6+ times per round at level 1.
Compare this to a game where at attack is "roll one die, add one number to it. Is it higher than their armour? Then roll a different die and add one number to it. That's the damage you deal".
Edit: Even those of us that love Shadowrun kinda hate Shadowrun. There was also a time when the guy in charge stole a bunch of money from the company, and they didn't have the fund to pay the people who actually worked on their games.
https://www.tgdmb.com/phpBB3/viewtopic.php?t=50989
https://hackslashmaster.blogspot.com/search/label/Shadowrun
IIRC first edition either forgot the rules to character creation or just forgot the table used.
And the book is horrible. Want to throw a grenade? Let me check under grenades... No, not there. Let's check under the throwing skills. Nope, no throwing rules for weapons. Well, maybe under attacks? No, that doesn't have grenade throwing rules either.
Oh look, here in a completely seperate section, contained in an unlisted sidebar, are the rules on grenade throwing.
Wait I found a reference to the page...and it's not actually the right one.
Want to build an explosive? Here's an equation you haven't seen since 9th grade that determines how big an explosive you can build.
Or in some editions:
Add to that injury rules.
Oh, you've been shot? It's going to be nearly impossible to cast a spell or fight back. Maybe realistic but the number of characters I spent multiple hours making only to be wounded within moments of play was... greater than two.
It has been a few decades.
I only did SR5, which wasn't that brutal, but SR4 or SR3 might've been more deadly
My RPG heyday was in and after high school, so 90-94. 1st or 2nd edition.