I LOVE the way this game looks. It's that specific late 90's aesthetics where fidely started to go up but details were still relatively low - one game in particular, SHOGO comes to my mind. The visuals are nice and clean, hit indicators are clear. Guns feel different enough but all of them are useful and pack a punch in their own way.
I did come across a couple issues however: first thing that I've noticed is that enemies don't seem to react to noise/gunshot, even when they're relatively close. This is most apparent in the shop in the first level, where you can shotgun the gunners down one by one as the rest keeps browsing like nothing happened. Their cone of vision seems fairly low as well.
Another issue, specifically with the gunners is that once they are shooting, their turning speed is way too low. They have no problem facing me while running, but once they start shooting you can easily run behind them as they slowly and awkwardly start to inch their direction towards you.
Had a bug on the first level that the water in the basement didn't render at all, so was quite confused when I started to swim in the air suddenly.
For the second level, I know you mentioned that enemy variety is lacking but what was missing in my opinion for those wide open areas are enemies that shoot slower projectiles you have to dodge. Melee enemies are not that much of a threat (unless sneaking up on you) and the gunners with their fast projectiles (or hitscan, though it didn't feel like they are) are way too opressive because of the large distances.