I'unno, I finally got around to buying the game like... last week? Week before? Seen some gameplay footage but that was about it for exposure, iirc. Went ahead and kicked on the beta, second run was 5 floor normal win with redshift (first was one of the other mechs, died before floor 3, heh). Think it was 502, at the time. Wasn't too bad, though it was pretty incredibly tedious -- ended up with basically garbage for damage perks or weapons, so the whole run took about four hours, or somethin' silly like that. Warden was like a 20-30 minute slog of constant firing. But it was a normal win in the beta, heh, and not what I'd call too terribly difficult. And that's being complete pants at bullet hells as well.
... now, my reflexes being about five different kinds of shot these days, any other mech I've played on normal since has been ground into the dirt unless I got freakishly lucky with perks or felt like rolling my face on things and tagged in the memory editor, but it feels like someone with steadier hands than I've got nowadays could manage without that much trouble.
Hard I haven't really poked at much yet without giving myself little things like infinite ammo, though. Probably will give a real try at it (i.e. a proper redshift run) if I can puzzle out that move/shoot linkage thing... or get fed up with that and just go for it without, heh.
Not sure what that means for balance, though. Redshift's a lot easier for me than the other mechs, so I can't really tell how over/under tuned things are. Some stuff definitely feels a bit too bullet sponge-y (rusted... something or other. Cores, sideshot, others I can't really remember the name of, some of the bosses, etc., etc.) if you don't happen to get some pretty serious damage buffs (via better weapons or just +% stuff), but that's about the worst I've noticed on normal, personally.