How to finsh the extra levels? I defeat everyone except for one enemy that shows up on HUD, but I can't find him (almost like he'd be invisible) and he does not fire on me. Is this a bug or... ?

Hi all. Does this game have an option to invert the Y-axis of the mouse?

Can't seem to get my T.Flight Stick to work correctly. Steam does detect it. What am I doing wrong??

https://gamefaqs.akamaized.net/box/7/6/5/27765_front.jpg

Gave it to a friend of mine and he said the mouse controls feel kinda sluggish. Any chance we get to get more options for controls?