Great as always, I'll list my thoughts on the new content:
The scattergun is okay, but I think it should be able to one-shot the smaller mechs up close.
The railgun is amazing. It's a bit overpowered because enemies can't really do anything when you one-shot them from behind cover, but damn is it satisfying.
Grenades are also fun and satisfying to land, their damage is appropriate and I really like the aiming visuals.
The new level looks great and I like that the new enemies have a mobility edge on the player, but with all the weapons and ammo you have no lone enemy is ever going to feel threatening.
I'd consider pulling a uno-reverse on the player and adding an indirect enemy that fires at you from behind cover.
The hovercraft is so much louder than anything else.