To be clear, the mod is really impressive.. but only from a technical standpoint. Otherwise, it's a rather tedious slog that's marred with weapons that don't really fit mechanically, a way-too-fragile character, and a final boss that just sucks plain and simple.

All of the modded weapons in the campaign are decked out with tacti-cool attachments like scopes and other stuff, meaning their Sweet Spots are roughly on par with the base game's LMGs and hardly able to be used effectively in close range. That wouldn't be so bad if say, 90% of the campaign's fights didn't take place in close quarters, that said those fights weren't typically made up of enemies with fairly chunky Tac-Bars and multiple Corpus, and that the enemies weren't coded to magdump their way through your own Tac-Bar.

It also wouldn't be so bad if your character didn't have a foot in the grave at all times. I think if that the content was better balanced, the dynamic of being a relatively fragile foot soldier with only two Corpus would be perfectly fine, but as it stands you're way too easy to take down relative to squads of military-grade killers sent to stop you. All it takes is one mistake for that first health bar to go, and generally being in that situation means that the second will follow not long after. Sounds cool on paper, feels awful in practice.

The final boss of Act 3 is just terrible. It's the culmination of the prior two issues with an added cherry-on-top of cringeworthy taunts and a "I'm the mod author's edgy OC" design. He's literally named Apex Fury for god's sake. He gets his own fancy Patriot style LMG which he constantly fires at you whenever you're in his line of sight (shredding your tac-bar and eventually you too), has his own special takedown where you have to go grab a barely visible custom weapon and stick it in him from behind twice over, and worst of all, his third phase has a riot shield combined with a revolver with an incredibly short dodge window.

TL;DR give the modded weapons tighter sweet spots, train N51 in trigger discipline, make the protag sturdier than a piece of cardboard by default, replace the OC entirely or at least remove his third phase