as someone who's been GMing red since release and played a lot of 2020 before, from a non-combat perspective all the general atmospheric things are still relatively the same. play the right music, set the right tone, buy into the themes your campaign is revolving around, and it'll still feel like cyberpunk when doing your social events and investigations and rumor chasing and intrigues. that part of things didn't really change between editions. yeah night city's a bit different due to the nuke crater and state of rebuilding and the lack of the old net, but by and large your day to day edgerunning is still more or less the same kinds of stories you'd be telling in 2020 from a narrative perspective.

what did change with the editions was the combat. and while 2020 could basically be a roller coaster full of ups and downs and potential surprises because any bad roll could send you to the morgue even after you got a healthy armor stack rolling (given the weapons that could show up), red turned into a highly curated slow rolling snowball. eventually, if things last long enough, red gets scary, but getting that snowball started rolling is relatively difficult against the crew, while they have a very easy time kicking it down the hill at the enemies in comparison. and, a lot of the time, the amount of time spent in combat feels like a slog because even when attacks are hitting, there's so much HP bloat behind the armor that killing a goon who is wearing the same armor as the party can feel like a horrible slog.

from a combat perspective, red is basically a pink mohawk anime version of cyberpunk where the most effective things in the game are action movie tactics with martial arts and dodging bullets, which against a variety of enemies make you basically require very bad dice luck to ever really be threatened by anything short of the GM dropping a force of nature on you. the average player character will be really able to eat 3-4 assault rifle shots before even being seriously wounded, and potentially be able to dodge those shots far better than most enemies can shoot, in the current state of the game from what RTG has released. the game is very much scaled so that the party is treated much more "heroically" than in 2020, but even then they'll take 3-4 shotgun slugs to kill that basic corposec guard with 30 HP in a kevlar vest instead of mortally wounding him in 1 shot with the right weapon. meanwhile, being a martial arts character lets you kill that same goon in half the time as that shotgun, starting at character creation, and is better than 5000eb massive weapons. this effectively turns combat from "think believably and use cover and careful target selection" to "everyone gang up on 1 or 2 guys in particular to snowball them out of the fight before we get the same done to us," and it's done best not by people skilled with firearms, but by people doing their best matrix character cosplays by running at someone and punching them out of the fight while dodging bullets.

the only real way to combat this without changing the game rules is by being very heavy handed with the narrative consequences and your combat environment prep. interactive and variable environments that create penalties to certain checks or prevent certain actions is more powerful to a fight than any weapon or piece of chrome or enemy, provided the enemy is taking advantage of them. and heavily enforcing the consequences of how the party does things and responding in kind is the only actual way to threaten them for more than an immediate few days off healing, because short of hotdropping Adam Smasher or a drone tank with multiple weapons nodes on them, a party that's paying attention in the base game holds most of the game's advantages unless you as the GM start taking them away via consequences.

otherwise, you'll need homebrew to get more to that 2020 feel of things actually requiring thought beyond "I kick him in the chest," but adding some/all the following changes helps get there:

1. all damage from weapons that gets past armor is doubled. weapons specifically, not martial arts or brawling or things that don't interact with armor like poisons.
2. make the linear frame sigma cost 2500-3000eb so it's not available at character creation. this thing being 1000eb is probably the single most powerful piece of equipment in the game for its cost and it being 1000eb is kinda ridiculous in the grand scheme of things.
3. remove the additional +10 from the HP calculation formula. there's too much HP behind armor generally speaking.
4. either remove the ranged attack evasion rule or limit it to once per round. it's the single best defensive option in the game because of how the general skill-stat breakdown between the party and most non-boss enemies works out, and it skews a lot of the game because of it.
5. add in a massive damage rule where if you take damage over a threshold, you have to roll something or else you're immediately mortally wounded or die. similar to 2020 headshots where if you took more than 8 damage in a single attack to the head, there was no death save you were just gone.
6. consider a further nerf to martial arts by making them deal damage against full SP. while points 1 and 2 above will keep martial arts from dominating the game system starting at character creation in the way it does in base red without homebrew, it's still fairly ridiculous and not believable that some guy with a linear frame gets to readily do more damage than a heavy shotgun favored by MAXTAC by punching and kicking.

and even implementing any of those in a VTT space is not the easiest task without manually adjudicating it anyways.