Felt like the second level is too big. Like - maybe twice the size? Definitely outstayed it's welcome, especially compared to the first level.
The dogs deal too much damage, in my opinion, and too fast. And the flamethrower is not fun to use - feels really underpowered. However I think this can be changed with proper balancing.
Flamer guys don't react if they get shot from far away. Dunno if it's a bug or not.
I really like overall design of this game. It feels cohesive, somehow. Enemy designs are very different and easy to read even if they are far away, which is good for prioritizing targets. So overall - I liked it. Keep it up!