Wonderful Game...
It had great new concept and reminded of the arcade games where you point and shoot. Could've been longer, but I understand how difficult this must've been. I have three suggestions for Killego 2:
1: Maybe it could be a top-down where you control the character (if that's too hard, stick with the shooter you have here).
2: Don't give too many instructions! Let the player try to figure out the correct thing to do and give multiple ways of doing it (without telling us how).
3: Different weapons. Perhaps when you find one (by going a different path [maybe you could choose paths]) you have a limited amount of ammo for it, until you find some, and you could switch in between your weapons. There could be areas where there's a Rocket Launcher icon on the wall, and if you have it, you could skip through entire areas or find a stash of hidden ammo and health packs.
I look forward to the next one!