One issue that I've noticed over and over again is that weapons/things capable of causing enemies/bosses to delay their attacks more are more than a little dramatically OP. I keep meaning to bring this up (it's been very OP since the game came out, it's not a recent thing), I keep forgetting. Main weapons in particular should probably never be able to do this ; sub weapons.... also probably shouldn't do this unless they are secret room only. No matter how strong an enemy is, this effect makes them very easy. That shotgun he had in that second run basically makes you unstoppable simply due to it existing. The more energy you then have with it, the crazier it gets. The damage on it was tremendous, too. But even with low damage it'd still produce that result. And that's against bosses: Normal things may as well not even exist against that gun.
It would be nice to have a function that allows some entities to have immunity to special effects like that. Mostly though, the "stun" effect as this seems to be called, seems like the sort of thing that should be restricted to consumables.
The crit on that flamethrower might also be an issue. Sniper Protocol + most weapons isn't THAT big of an increase, but it seems to be with the flamethrower due to it's wild fire rate. I really need to do more test runs with this particular mech myself, have kinda neglected that one.
Worth noting that the next video also includes extremely high damage again.
Scrap Collector's description needs changing. Should be "heal" instead of "gain", on that one.